Merge pull request #19 from crowbar/release/pebbles/master

pull changes from dell
if user specifies raw not local and there are no disks available I expect it to fails and return some sensible error, like " no raw storage available". It should not automatically switch to a different mode that is not specified by user
Stop installing python-keystone package

This is not needed since commit 6921bbb, when we moved to using
keystoneclient.middleware.auth_token.
Merge pull request #53 from MirantisDellCrowbar/release/pebbles/unstable/master

Disable fallback to "local" storage when there is no disks available
Merge pull request #54 from vuntz/no-python-keystone

Stop installing python-keystone package