Refactor REST API to work on top of DB API

Refactored REST API for Stories and Projects to work on top of DB API layer.

Details:
* Moved wsme model to corresponding controller files
* Added func tests for '/stories' and '/projects'

Change-Id: If8743db33da753be067c47b56aba0812f6bdf913
Merge "Refactor REST API to work on top of DB API"