Upgrade django_tables2 to 1.6.0

[bellwood]

django_tables2 now has an option to render responsive tables via bootstrap via either:

{% render_table table "django_tables2/bootstrap-responsive.html" %}

or

class MyTable(tables.Table):
    class Meta:
        template = 'django_tables2/bootstrap-responsive.html'

This would greatly improve the tables in use especially on smaller screen devices.

Thanks =)