Numerapi

- support passing `round_num` to `list_datasets`, to get available files from past rounds
- `download_dataset` no longer requires a destination path, it defaults to the source file name
- `download_dataset` now accepts a `round_num` argument, to download old files
- added `upload_diagnostics` to upload to the new diagnostics tool
- added `diagnostics` to fetch results of a diagnostics run

- Add version arg to upload_predictions (59)

- added `list_datasets` to fetch the list of available data files
- added `download_dataset` to download files from the new data api
- add missing documentation and deprecation warnings

- Add mmc20d rep and rank to SignalsAPI daily_model_performances
- rename `corr_20d*` to `corr20d*` since Numerai's GraphQL adapter now handles numbers in fields without underscores

- adding `fncPercentile`, `mmcPercentile` & `corrPercentile` to `daily_submissions_performances`
- replace deprecated GraphQL `v2UserProfile` call with `v3UserProfile`
- replace deprecated GraphQL `signalsUserProfile` call with `v2SignalsProfile`
- new `daily_model_performances`, replacing `daily_user_performances`
- signals: new `daily_model_performances`, replacing `daily_user_performances`
- update & fix command line interface

- cli: remove deprecated 'payments' and 'user-activities' commands (51)
- cli: converting the output to JSON (52)