Docs: Fix the path to the controllers

This was restructured, but the docs were not updated.

Change-Id: Ie0d04de234d1616f574805c43d5a4c6525e547fc
Closes-bug: #1255315
Add sphinxcontirb-httpdomain to the test-requirements

This is needed to build the auto generated API docs.

Change-Id: I662fc88c566b23b2dd315b97f457dc3e653a29ec