Refaktor

Created a testing app for bb_projects. 
Commented some factory stuff and imports of unused models (e.g. ProjectDetailField).
Updated the testing.py settings file to set PROJECTS_PROJECT_MODEL and other variables so that tests run well. 
Simplified the TestCase for testing abstract models. We don't need the complicated setup and teardown methods. We can simply add the testing app to INSTALLED_APPS in the testing.py settings file.