cannot work after install and config in GitHub EE

Followed this [https://medium.com/buildbot/using-hyper-sh-to-deploy-your-buildbot-126888e1164d](https://medium.com/buildbot/using-hyper-sh-to-deploy-your-buildbot-126888e1164d) I config this by webUI, set number of local workers to 8, then generate tokens, webhook (push and PR), set payload URL, then delivery payload, github EE show me `200, success`


My `.travis.yml`:

```yml
script:
- echo 'test CI'
```

then, when I push to this repo, github EE webhooks show me `500, failed`


This is `twistd.log`:

```log
2018-01-08 15:24:52+0800 [_GenericHTTPChannelProtocol,39,10.200.55.139] X-GitHub-Event: push
2018-01-08 15:24:52+0800 [_GenericHTTPChannelProtocol,39,10.200.55.139] New revision: 21126b0f
2018-01-08 15:24:52+0800 [_GenericHTTPChannelProtocol,39,10.200.55.139] adding changes from web hook
Traceback (most recent call last):
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot/www/hooks/github.py", line 334, in getChanges
return self.handler.process(request)
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/twisted/internet/defer.py", line 1532, in unwindGenerator
return _inlineCallbacks(None, gen, Deferred())
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/twisted/internet/defer.py", line 1386, in _inlineCallbacks
result = g.send(result)
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot/www/hooks/github.py", line 89, in process
result = yield defer.maybeDeferred(lambda: handler(payload, event_type))
--- ---
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/twisted/internet/defer.py", line 150, in maybeDeferred
result = f(*args, **kw)
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot/www/hooks/github.py", line 89, in
result = yield defer.maybeDeferred(lambda: handler(payload, event_type))
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot/www/hooks/github.py", line 149, in handle_push
event, properties)
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot/www/hooks/github.py", line 287, in _process_change
change['codebase'] = self._codebase(payload)
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot_travis/vcs/github.py", line 28, in getCodebaseForGitHubChange
return getCodebaseForRepository(payload['repository']['html_url'])
File "/Users/xxx/BuildBot/bb-travis/sandbox/lib/python3.6/site-packages/buildbot_travis/vcs/base.py", line 178, in getCodebaseForRepository
return repository_db_by_url[url].name
builtins.KeyError: u''
```

But when I force build it, builder will block, can only show `preparing worker`. And I cannot stop this builder.

Do I missing some steps?