ClusterHQ/flocker — pull request #1020 by tomprince (2014-12-16 00:10:05+00:00)
Title: [FLOC-143] Skip conch using tests, if not available.

https://clusterhq.atlassian.net/browse/FLOC-143

`flocker.testtools` currently depends on `twisted.conch` which requires PyCrypto. This isn't installed in the virtualenv the omnibus package generates. Factor things, so `testtools` can be imported if PyCrypto isn't installed.