Replaced AccountUser and AccountGroup to resource app
Changed sites relation of Resource model from AccountSite to Site
Renamed AccountGroup to Group
Removed GroupViewSet
Removed all AccountGroup occurrences to Group
Made Group (custom) inherit from Resource
Created a unique serializer for user and accountuser. Now can create a user through accountuser
Renamed AccountUser model to User. Removed User (from auth) API. Moving on with #106
Renamed all AccountUser occurrences to User #106
Changed User to inherit from Resource #106
Renamed AccountSite to Site #106
Made Site inherit from Resource #106
Moved almost everything from account to resource app #106
Removed Account app #106
Changed model_name field to model in category app
All models that use category were ported to use content type
Finished changes and closed #106
Merged Category changes
Merge pull request #111 from henriquecf/106-change-accountuser-accountgroup-accountsite-resourceuser-resourcegroup-resourcesite

106 change accountuser accountgroup accountsite resourceuser resourcegroup resourcesite
Merged master into #107