Python 3: use six.iteritems()

Change-Id: I9d86dd948bc2241bbb69a04c0024f90b805d7cc8
Update theme for docs

The current developer docs theme used is out of sync with the other
openstack projects. This patch will update the docs to provide a more
consistent look and feel when using developer docs

Change-Id: I03985039381c2ba4f81a2015258f7b49bba441d9
Merge "Update theme for docs"
Merge "Python 3: use six.iteritems()"