Start refactoring of the trigger system:

- Move each trigger handler into its own file
- Add dictionary helper classes for easier reading and writing of dict-based data
- Extract the web hook payload -> internal representation building for each trigger system
- Add tests for this transformation
- Remove support for Github archived-based building

util/migrate/migratebitbucketservices.py

@@ -5,7 +5,7 @@ from app import app
 from data.database import configure, BaseModel, uuid_generator
 from peewee import *
 from bitbucket import BitBucket
-from endpoints.trigger import BitbucketBuildTrigger
+from buildtrigger.bitbuckethandler import BitbucketBuildTrigger
 
 configure(app.config)