Automate integration tests

Our current integration test suite is large and comprehensive but is only runnable manually. OSS folks who open PRs can't run them and it's a big process for us to run them manually. Make it possible to trigger integration tests.

For integration tests to run:
* `ironcore-id` needs to be running locally with its postgres DB
* project, assertion key, and segment info that is valid on that `ironcore-id` instance needs to be in `integration/projects/project.json` (can probably be canned DB scripts)
* https certs for `dev1.scrambledbits.org` need to be up to date (automating this is the hardest part)
* `yarn start` needs to run the integration app
* `yarn nightwatch` can then run the suite, though that requires `chrome` to be installed so `chromedriver` works

A possible workaround to the https certs issue would be to make the integration app not require https, but the scope of that is unknown at the time of writing this ticket.