Chapter Page Rework and Multi Environment Rework

The application now supports deploying to heroku using a persistent store (currently the free postgres instance).  This meant creating 2 Github applications to support OAuth in testing/dev and production.  

- Various environment variables now required in all environments.  The `export_dev_keys.sh` can be `source`d to set up the test environment with a test application we have provided (so as not to interfere with the "real thing")
- Seeding of development database with 2 chapters (London and Belfast) is now done in a migration rather than `Global.onStart` - which has been removed
- When you leave a chapter, all your suggestions get deleted from that chapter.  Perhaps this is too harsh?  Maybe we should put this on a delayed batch job to prevent accidents and ragequits? 
- The user now stores some extra goodies (avatar, full name etc.).  Not sure how this should be refreshed
- Notes in suggestions now support markdown (performed when the form is bound during posting of the suggestion)
- Chapter page now has some tweaks including showing the users who are members