Edx-sga

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- Temporarily disable integration and Python 2 tests (267)
- Added missing decode to resource loading
- Fixed build error involving jsonfield import in edx-submissions

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- Ran python-modernizer on repo (256)

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- Possible fix for copying units with SGA (254)
- Correct the courseware imports
- Added focus to file upload error message (241)
- Recreated submissions zip file when student(s) score reset (239)
- Fixed race condition when removing grades SGA (117)

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- Fix integration tests under Django 1.11 (247)

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- Added tests to validate all student submissions (235)
- Added url encoding in file name (236)
- Added support email to the error message on zip submissions download (234)
- Fixed comma in file name (237)
- Fixed Django 1.11 related issue in test (238)
- Fixed zipping large files for staff submissions. (226) (230)
- Fixed zipping large files for staff submissions. (226)
- Update README.md
- Update README.md