Added Devise to User
Added main controller
Spelling
Enforce i18n locale validation
Rescue from missing parameters
Added decode_json method to test helpers
Removed Jbuilder, added active_model_serializers
Added group api (controller, tests, serializer, routes)
Updated group controller tests and removed unneeded before_filter in controller
Added Employee API
Added Request API
Added assertion in GroupsController tests
Merge branch 'api-development'