add push_to_lms to Studio; uses MITX_FEATURES['ENABLE_PUSH_TO_LMS']
Push To LMS updates
Added tests
Converted scripts to django commands
Removed advanced module requirement
Generalized to platform
Switched to subprocess for shell commands
Beefed up resiliency and error checking.
Refactored since #1910 removed get_location_and_verify_access
Added settings to aws for export directory and reworked test setup and teardown
Several review based fixes
Added line to Changelog
Changed URL handler to be accepting and moved git bare repo inside of test_root/data
Added exception logging to help trace issues
Added output in exception logging
Made the branch to commit to explicit instead of implicit
Skipping git identity test on condition of global configuration set
Major refactor and rename of feature
All forward facing wording changed to Export to Git
Export to git functions removed from management command and put in common file
Additional error checking and documentation improvements
Nitpicks and other minor fixes
Merge pull request #718 from edx/feature/ichuang/push-to-lms

Let a Studio user export course to git (and via git, to elsewhere, eg LMS)