Feature/sslrequiredmixin

[chrisjones-brack3t]

SSLRequiredMixin

Addresses #108

• New SSLRequiredMixin.
  • Redirects http -> https
  • Optionally, set view.raise_exception = True to raise a 404 instead of redirecting.
  • If DEBUG=True the SSL mixin is bypassed.
• 100% test coverage.
• Added Docs.
  • Updated the docs theme from default to alabaster
• Drop support for Django 1.4. Updated tox.
• Importing Django.VERSION instead of the whole of Django for version checking in tests.

[kennethlove]

Change SSLRequiredMixin to

:ref:`SSLRequiredMixin`