Adding support for checking context for implicit and explicit access.

Merge pull request #14 from edx/bexline/context_checking

Updating the authorization decorator

Updating the permission_required decorator with an additional argument

Adding in mixin for authz support

Merge pull request #12 from edx/cpappas/EN-1695

ENT-1695 - Adding in mixin for authz support

Decorator for authentication

Adding a decorator for supporting authentication permissions.

Merge pull request #8 from edx/bexline/swur_django_admin

Adding django admin support for models extending UserRoleAssignment.

Adding helper utils for interactions with the jwt and database

Merge pull request #4 from edx/cpappas/ENT-1557

ENT-1557 | Updating utils files with helper methods

Merge pull request #7 from edx/bexline/add_context

Adding get_context to the UserRoleAssignment class.

Quality fixes

Getting travis builds to be green

Changes to models

Merge pull request #5 from edx/cpappas/version-bump

Update CHANGELOG.rst

Merge pull request #1 from edx/cpappas/ENT-1555

ENT-1555 | Adding in some of the base models being worked on in the lms