Infrastructure update

* Update Openstack common (aa7c658156e1e46315cdce1d580718f30054da2f):
- apiclient
- importutils
- strutils
- jsonutils
- cliutils
- apiclient
* Switch from nosetests to testtools
* Update shell.py to the actual state
Change-Id: I2b8f3393ba3e700f65f1a794caae713f12856035