Removed extra column in table
Updated PK declaration signature
Added User's table
Added gradle tasks for creating/dropping schema
Moved tests util class into common test module
The most base entity and helper class were implemented
User entity has been mapped
Added relation for User in TimeTag
Added tests for saving functionality for TimeTag and User
Introduced user entity into UI
Implement simple DAO to work with User entity
Merge branch 'model_rethinking'