Add templatecheck test to tox

Ghost User
2016-08-12T16:46:19+02:00

Closes #46

As this is a new package, it could be useful to quickly glance over [joostrijneveld/django-template-check](https://github.com/joostrijneveld/django-template-check/blob/master/django_template_check/management/commands/templatecheck.py) as well.