Numerapi

- add v2 version of `get_leaderboard`
- add `stake_get` & `stake_set`
- add `stake_increase`, `stake_decrease` & `stake_drain`
- add `public_user_profile`
- add `daily_user_performances`
- add `daily_submissions_performances`
- remove v1 staking
- remove `get_staking_cutoff` - no longer relevant
- old `get_leaderboard` renamed to `get_v1_leaderboard`
- add v2-style staking to cli interface
- update documentation

- remove phone number and bonus fetching (16)

- fix downloading dataset for tournaments > 1
- add `validationCorrelation` and `liveCorrelation` to all relevant places
- remove `validationAuroc` and `validationLogloss` from `submission_status`

- default to tournament 8 `katzuagi`
- update docstring
- added `reputationPayments`,

- include `otherUsdIssuances` and `phoneVerificationBonus` to `get_payments`
- add datetime information (`insertedAt`) to `get_transactions`

- return new `reputation` as announced by numerai on 2019-05-29 in `get_rankings`