Update per review
Add `@property`
Adding whitespace
Removing whitespace
Update imports
Change edge.edx.org to example.edu
Add new lines
ImportError code path did not actually work due to missing definition of extra. Added error messages.
Moved extra declaration to line 121 per iceraj's request.
Merge pull request #8 from william-silversmith/ws_import_error

Fixing ImportError Code Path in setup.py
Adding note to post_message2 related to https://openedx.atlassian.net/browse/PLAT-281
Merge pull request #6 from mitodl/feature/lti_2_edx

READY FOR REVIEW: PyLTI edX LTI 2.0 support
Merge branch 'develop' into feature/docs