Using django-markwhat as a drop-in replacement

for ``django.contirb.markup`` since it's deprecated.

From django-markwhat docs:

Extracted from `Django 1.4 since markup deprecation <https://docs.djangoproject.com/en/dev/releases/1.5/#django-contrib-markup>`_

Supported Python versions
=========================

``django-crequest`` currently can be run on multiple python versions:

* Python 2 (2.7)
* Python 3 (3.2, 3.3, 3.4)
* PyPy