Added essential field to application base class. Wrote registry method to return non-essential apps.
PEP8 fixes.
Added method to handle on websocket close.
Adjusted comment.
Merge branch 'develop' into on_close_method
Renaming function and adding .rdb to .gitignore.
Fix URL for requireJS
Merge pull request #62 from jivid/requirejs_hotfix

Fix URL for requireJS
Merge branch 'develop' into on_close_method
Remove .rdb.
Renamed get_non_essential_apps method. Modified null check per code review.
Added on_client_leave as function as callback.
Merge branch 'develop' into non_essential_apps
Renamed non_essential_apps to use private modifier.
Register websocket as part of socket leave.
Comment fixes and style conventions.
Merge pull request #58 from jivid/on_close_method

on_socket_close()
Merge pull request #57 from jivid/non_essential_apps

Added get_non_essential_apps() method.
merge conflicts.