Added customized permission and authentication.
Updated test
Refactor packages. Removed unnecessary modulization of views.
Replaced django-restframework-docs with swagger.
Added permission.
Added people view.
Added friends view.
Rename peoplePermission to isFriend
Use view based permission instead of permission_classes
Added url for people/{user_id}/activities
Updated URLs for AuthViews.
Added get activities/{acitvity_id} function.
Added activities/{activity_id}/comments url.
Added activities/{activity_id}/participants
Added post activities/{activity_id}/comments.