Fix imports for Django 1.6 and above
Fix imports for Django 1.6 and above

GradConnection/djangosaml2,WiserTogether/djangosaml2,WiserTogether/djangosaml2,kviktor/djangosaml2-py3,GradConnection/djangosaml2,City-of-Helsinki/djangosaml2,shabda/djangosaml2,shabda/djangosaml2,kviktor/djangosaml2-py3,City-of-Helsinki/djangosaml2,advisory/djangosaml2_tenant,advisory/djangosaml2_tenant