Fix syntax error with database migration.
Serve the index.html file by default from public.
Remove User model completely.

After thinking about it I do not think the first draft of this API needs
to have User authentication et al. I think that basically hooking us up
to the GitHub webhook should be more than enough.
Add Webhook endpoint for GitHub callbacks.

Modifies heavily the API endpoint and adding webhook with Gear releases
from the GH repository hook.