Unpin kazoo

There doesn't seem to be a reason to pin to a
year old version of kazoo since other projects
would like to use the newer version its safer
just to unpin the version restriction.

Change-Id: I7c5a74e06f604ce89f0de0a4b01a8f7be41d70a2
Update python-keystoneclient to 0.5.0

A new version of keystoneclient was released containing changes we
wish to use in Heat, so bump to the latest version.

Change-Id: I62fe2363e97df9a8825c91ba67a1d86c927eaf22
Merge "Unpin kazoo"
Merge "Add XenAPI to OpenStack dependencies"
Merge "Update python-keystoneclient to 0.5.0"