wip model refactor
moved over to using models
test fixes and committing in a few tests where needed
some basic tests for the starting of a draft via a message
Merge branch 'wip_model_refactor'

Conflicts:
	drafts_as_a_service/sa.py
	drafts_as_a_service/tests/conftest.py
	drafts_as_a_service/tests/test_draft.py
	drafts_as_a_service/tests/twitter/test_start.py
	drafts_as_a_service/twitter.py