Numerapi

- bugfix, timeout for http requests was accidently set to 3 seconds.

- make downloads more robust and prevent broken files by downloading to temporary files
- simple retry mechanism for failed API requests (5xx error codes only)
- Remove submission `version` parameter (PR 75)

- add tc, fnc, fncV3 to get_leaderboard
- add icRank, icRep to SignalsAPI.get_leaderboard
- add tcRank, tcRep, fncV3Rep and fncV3Rank to daily_model_performances
- add icRep and icRank to SignalsAPI.daily_model_performances
- add tc and tcPercentile to daily_submissions_performances
- make `stake_set` work with multi model accounts
- add tc to the round_model_performances method (PR 74)
- add tcPercentile, ic, icPercentile, fncV3, fncV3Percentile to round_model_performances

- added `set_bio` to programmatically update the bio field for some model
- added `set_link` to programmatically update the user link field
- enable stake changes for Numerai Signals (68 Thx habakan)
- run tests via github actions and disable travis integration

- cli: fix predictions upload

- cli: support uploading predictions generated with the new dataset (needs `--new_data`)
- signals: make `round_model_performances` available