Initial work for pulp_openstack.

This will lay down the CLI plugin and allow uploading of images. Thanks to
@rbarlow for the detailed review.

NOTE: this runs unit tests but will not fail the build if they fail. Please use
a local unit test run as the authoritative source. Flake8 and certain pep257
errors *will* fail the build however.
Merge pull request #1 from beav/initial

Initial commit for pulp_openstack