Collected works of Nova_Callback

This is the squashed version and possiby end result of the
    Nova Callback Filter.

Internally known as RM5109
Merge pull request #21 from insequent/nova_callback

Adding Nova Callbacks
Respect tenant info from repose

RM7001

Turns out getting the admin roles is ok.

Added tests.

Changed version to 0.1.3

Refactored a tiny bit

Modified some old tests. I don't know what I was doing with the sets. copypasta
ftl. :(
Merge pull request #23 from roaet/respect_tenant_information

Respect tenant info from repose