Added the ability to build docs on Django 1.11 and Python 3.
Review Request #9742 — Created March 5, 2018 and submitted
Our documentation building support has been updated to allow us to
generate docs against Django 1.11 and Python 3. The main Djblets
documentation needed to import models from Django apps that weren't yet
set up, causing various issues with autodoc generation. This was
resolved by setting up Django (needed in Django 1.7+) before any imports
There were further errors at that point due to the lack of certain apps
INSTALLED_APPS. These have been added.
Finally, the Makefiles for the doc packages now allow the Python version
to be overridden, letting us build on any version of Python we choose.
Successfully built all doc bundles using Python 2.7, 3.4, 3.5, and 3.6
across Django 1.6 and 1.11.