Backporting fixes:
- Fix _version location for sdist. #2729 by @jaheba
- Fix version cmdclass handling. #2735 by @jaheba
- Remove usage of glide in tsf-reader. #2737 by @jaheba
- Fix: use non-strict inequality in definition of coverage #2738 by @lostella
- Fix MXNet NOPScaler #2744 by @abdulfatir
- Add scipy requirement #2745 by @abdulfatir
- Fix dataset file discovery. #2777 by @jaheba
- Fix: Loading of nested paths in FileDataset. #2779 by @jaheba
- Prophet: Pass 'item_id' and 'info' to forecast. #2780 by @jaheba
- Test: Set caplog level for shell tests. #2786 by @jaheba