Unauthorized Access when getting default_external_group

I get this error fairly consistently when the boarding heroku app has been up for a while. My guess is that the session's authorization has timed out and needs to be refreshed. What would be a good fix for this?

```
#
2017-04-26T06:16:18.894462+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/client.rb:624:in `block in send_request'
2017-04-26T06:16:18.894463+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/client.rb:463:in `with_retry'
2017-04-26T06:16:18.894464+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/client.rb:618:in `send_request'
2017-04-26T06:16:18.894465+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/client.rb:507:in `request'
2017-04-26T06:16:18.894465+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/test_flight/client.rb:92:in `get_groups'
2017-04-26T06:16:18.894466+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/test_flight/group.rb:16:in `all'
2017-04-26T06:16:18.894467+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/test_flight/group.rb:30:in `default_external_group'
2017-04-26T06:16:18.894467+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/fastlane-2.28.3/spaceship/lib/spaceship/tunes/application.rb:374:in `default_external_group'
2017-04-26T06:16:18.894468+00:00 app[web.1]: /app/app/controllers/invite_controller.rb:89:in `submit'
2017-04-26T06:16:18.894469+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
2017-04-26T06:16:18.894470+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/abstract_controller/base.rb:198:in `process_action'
2017-04-26T06:16:18.894470+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/rendering.rb:10:in `process_action'
2017-04-26T06:16:18.894471+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/abstract_controller/callbacks.rb:20:in `block in process_action'
2017-04-26T06:16:18.894472+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:117:in `call'
2017-04-26T06:16:18.894472+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:117:in `call'
2017-04-26T06:16:18.894473+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:555:in `block (2 levels) in compile'
2017-04-26T06:16:18.894473+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:505:in `call'
2017-04-26T06:16:18.894475+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:505:in `call'
2017-04-26T06:16:18.894475+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:92:in `_run_callbacks'
2017-04-26T06:16:18.894476+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:776:in `_run_process_action_callbacks'
2017-04-26T06:16:18.894477+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:81:in `run_callbacks'
2017-04-26T06:16:18.894477+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/abstract_controller/callbacks.rb:19:in `process_action'
2017-04-26T06:16:18.894478+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/rescue.rb:29:in `process_action'
2017-04-26T06:16:18.894479+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
2017-04-26T06:16:18.894480+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/notifications.rb:164:in `block in instrument'
2017-04-26T06:16:18.894481+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
2017-04-26T06:16:18.894482+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/notifications.rb:164:in `instrument'
2017-04-26T06:16:18.894482+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
2017-04-26T06:16:18.894483+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
2017-04-26T06:16:18.894484+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/abstract_controller/base.rb:137:in `process'
2017-04-26T06:16:18.894484+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionview-4.2.1/lib/action_view/rendering.rb:30:in `process'
2017-04-26T06:16:18.894485+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal.rb:196:in `dispatch'
2017-04-26T06:16:18.894486+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
2017-04-26T06:16:18.894486+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_controller/metal.rb:237:in `block in action'
2017-04-26T06:16:18.894487+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:74:in `call'
2017-04-26T06:16:18.894487+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:74:in `dispatch'
2017-04-26T06:16:18.894491+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:43:in `serve'
2017-04-26T06:16:18.894492+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/journey/router.rb:43:in `block in serve'
2017-04-26T06:16:18.894493+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/journey/router.rb:30:in `each'
2017-04-26T06:16:18.894493+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/journey/router.rb:30:in `serve'
2017-04-26T06:16:18.894494+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:819:in `call'
2017-04-26T06:16:18.894495+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/http_accept_language-2.0.5/lib/http_accept_language/middleware.rb:14:in `call'
2017-04-26T06:16:18.894512+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/etag.rb:24:in `call'
2017-04-26T06:16:18.894513+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/conditionalget.rb:38:in `call'
2017-04-26T06:16:18.894514+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/head.rb:13:in `call'
2017-04-26T06:16:18.894514+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/params_parser.rb:27:in `call'
2017-04-26T06:16:18.894515+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/flash.rb:260:in `call'
2017-04-26T06:16:18.894516+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/session/abstract/id.rb:225:in `context'
2017-04-26T06:16:18.894516+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/session/abstract/id.rb:220:in `call'
2017-04-26T06:16:18.894517+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/cookies.rb:560:in `call'
2017-04-26T06:16:18.894518+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
2017-04-26T06:16:18.894518+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:88:in `call'
2017-04-26T06:16:18.894519+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:88:in `_run_callbacks'
2017-04-26T06:16:18.894520+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:776:in `_run_call_callbacks'
2017-04-26T06:16:18.894520+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/callbacks.rb:81:in `run_callbacks'
2017-04-26T06:16:18.894521+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
2017-04-26T06:16:18.894522+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
2017-04-26T06:16:18.894528+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
2017-04-26T06:16:18.894529+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
2017-04-26T06:16:18.894530+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.1/lib/rails/rack/logger.rb:38:in `call_app'
2017-04-26T06:16:18.894531+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.1/lib/rails/rack/logger.rb:20:in `block in call'
2017-04-26T06:16:18.894532+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/tagged_logging.rb:68:in `block in tagged'
2017-04-26T06:16:18.894532+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/tagged_logging.rb:26:in `tagged'
2017-04-26T06:16:18.894533+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/tagged_logging.rb:68:in `tagged'
2017-04-26T06:16:18.894533+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.1/lib/rails/rack/logger.rb:20:in `call'
2017-04-26T06:16:18.894534+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/request_id.rb:21:in `call'
2017-04-26T06:16:18.894534+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/methodoverride.rb:22:in `call'
2017-04-26T06:16:18.894535+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/runtime.rb:18:in `call'
2017-04-26T06:16:18.894536+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.2.1/lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
2017-04-26T06:16:18.894537+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/static.rb:113:in `call'
2017-04-26T06:16:18.894538+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/rack-1.6.5/lib/rack/sendfile.rb:113:in `call'
2017-04-26T06:16:18.894538+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.1/lib/rails/engine.rb:518:in `call'
2017-04-26T06:16:18.894539+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.1/lib/rails/application.rb:164:in `call'
2017-04-26T06:16:18.894540+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/configuration.rb:225:in `call'
2017-04-26T06:16:18.894540+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/server.rb:578:in `handle_request'
2017-04-26T06:16:18.894541+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/server.rb:415:in `process_client'
2017-04-26T06:16:18.894546+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/server.rb:275:in `block in run'
2017-04-26T06:16:18.894546+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/thread_pool.rb:116:in `call'
2017-04-26T06:16:18.894547+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/puma-3.6.2/lib/puma/thread_pool.rb:116:in `block in spawn_thread'
2017-04-26T06:16:18.895511+00:00 app[web.1]: Rendered invite/index.html.erb within layouts/application (0.1ms)
2017-04-26T06:16:18.897628+00:00 app[web.1]: Completed 200 OK in 6884ms (Views: 2.8ms)
```