Make corresponding mixin for LTI roles being required.  Remove GroupRequiredMixin and LoginRequiredMixin since the former is not used in LTI requests and neither was being used currently anyway.  Require django_braces with this library and use it's LoginRequiredMixin instead.  Update version.
Merge pull request #1 from Harvard-University-iCommons/develop

Make corresponding mixin for LTI roles being required.  Remove GroupRequ...