Existing twitter transport
Added tests
Modified for auto response
pep8 fixes
Added newlines
Merge branch 'develop' into feature/issue-2-add-null-inbound-for-auto

Conflicts:
	vxtwitter/tests/test_twitter.py
	vxtwitter/twitter.py
Fixed comment, labels and made handle_folow an inline callback
Check if message gets published
Merge pull request #4 from praekelt/feature/issue-2-add-null-inbound-for-auto

Send vumi null inbound message to enable auto-response on follow