Add of a version variable in the main __init__ file

I added a version variable to bump when necessary. It will be used in
conjonction with the Changelog.
Signed-off-by: Matthieu Berjon <matthieu.berjon@inria.fr>

django/allgo/__init__.py

+# -*- coding: utf-8 -*-
+
+""" Top-level package for Allgo. """
+
+__version__ = '0.1.0'