Bump twisted up to 13.1
Change CQL version to follow the semver spec.

http://semver.org
Merge pull request #294 from rackerlabs/cassandra-test-semver-client

Change CQL version to follow the semver spec.
Merge pull request #291 from rackerlabs/twisted_13.1

Upgrade Twisted version 13.1 (ready for review)
Merge branch 'master' into upgrade-klein

Conflicts:
	requirements.txt