Flocker deploy 121

I would like this to be looked over by someone, for guidance on what needs to be done, and confirmation I'm on the right track.

And, now, the comment on #121 that some of this might not be necessary for now.

There are a couple of inline "TODO"s I'm not sure about.

Fixes #121 
You've re-used the same skip message that's caused so much confusion already :) Why not add a note to say that this test is skipped unless the environment variable "FLOCKER_INSTALLED" is set.