Updated django-debug-toolbar to 1.5 to fix

TypeError at /
process() missing 1 required positional argument: 'stream'

Related to https://github.com/jazzband/django-debug-toolbar/issues/856

Adds Django/PostgreSQL template with persistent storage.

bump to latest imagestream versions

enable whitenoise compression #3

Put Whitenoise back in settings.py

Add PIP_INDEX_URL option and fix required parameter issue

The new PIP_INDEX_URL parameter is added to allow custom PyPi mirror
URL to be used during the build process.

There are several paramaters that are required but didn't listed as
requested (*). Now, they are marked as required to be explicit.

Signed-off-by: Vu Dinh <vdinh@redhat.com>

Fix Django version incompatible for Python 3.3

docs: update python 33 to python 35

find_spec isn't available in Python 3.3; it was added in Python 3.4.

The current required Django version is 1.9.5 which doesn't support
Python 3.3 which causes the Python 3.3 deployment to fail while
using django-ex git repo.

The Django version is modified to use 1.8.x only to include Python
3.3 support.

Signed-off-by: Vu Dinh <vdinh@redhat.com>

update webhook instructions