Bitget fetchFundingRateHistory
Bitget fetchFundingRateHistory

Added fetchFundingRateHistory to Bitget:
```
bitget.fetchFundingRateHistory (BTC/USDT:USDT)
2022-05-13T01:58:59.377Z iteration 0 passed in 306 ms

       symbol | fundingRate |     timestamp |                 datetime
----------------------------------------------------------------------
BTC/USDT:USDT |      0.0001 | 1649545200000 | 2022-04-09T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649574000000 | 2022-04-10T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649602800000 | 2022-04-10T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649631600000 | 2022-04-10T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649660400000 | 2022-04-11T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649689200000 | 2022-04-11T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649718000000 | 2022-04-11T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649746800000 | 2022-04-12T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649775600000 | 2022-04-12T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649804400000 | 2022-04-12T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649833200000 | 2022-04-13T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649862000000 | 2022-04-13T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649890800000 | 2022-04-13T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649919600000 | 2022-04-14T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649948400000 | 2022-04-14T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1649977200000 | 2022-04-14T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650006000000 | 2022-04-15T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650034800000 | 2022-04-15T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650063600000 | 2022-04-15T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650092400000 | 2022-04-16T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650121200000 | 2022-04-16T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650150000000 | 2022-04-16T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650178800000 | 2022-04-17T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650207600000 | 2022-04-17T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650236400000 | 2022-04-17T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650265200000 | 2022-04-18T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650294000000 | 2022-04-18T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650322800000 | 2022-04-18T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650351600000 | 2022-04-19T07:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1650380400000 | 2022-04-19T15:00:00.000Z
BTC/USDT:USDT |   -0.000026 | 1650409200000 | 2022-04-19T23:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1650438000000 | 2022-04-20T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650466800000 | 2022-04-20T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650495600000 | 2022-04-20T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650524400000 | 2022-04-21T07:00:00.000Z
BTC/USDT:USDT |   -0.000025 | 1650553200000 | 2022-04-21T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650582000000 | 2022-04-21T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650610800000 | 2022-04-22T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650639600000 | 2022-04-22T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650668400000 | 2022-04-22T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650697200000 | 2022-04-23T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650726000000 | 2022-04-23T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650754800000 | 2022-04-23T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650783600000 | 2022-04-24T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650812400000 | 2022-04-24T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650841200000 | 2022-04-24T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650870000000 | 2022-04-25T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650898800000 | 2022-04-25T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650927600000 | 2022-04-25T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650956400000 | 2022-04-26T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1650985200000 | 2022-04-26T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651014000000 | 2022-04-26T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651042800000 | 2022-04-27T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651071600000 | 2022-04-27T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651100400000 | 2022-04-27T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651129200000 | 2022-04-28T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651158000000 | 2022-04-28T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651186800000 | 2022-04-28T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651215600000 | 2022-04-29T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651244400000 | 2022-04-29T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651273200000 | 2022-04-29T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651302000000 | 2022-04-30T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651330800000 | 2022-04-30T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651359600000 | 2022-04-30T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651388400000 | 2022-05-01T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651417200000 | 2022-05-01T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651446000000 | 2022-05-01T23:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1651474800000 | 2022-05-02T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651503600000 | 2022-05-02T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651532400000 | 2022-05-02T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651561200000 | 2022-05-03T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651590000000 | 2022-05-03T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651618800000 | 2022-05-03T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651647600000 | 2022-05-04T07:00:00.000Z
BTC/USDT:USDT |   -0.000065 | 1651676400000 | 2022-05-04T15:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1651705200000 | 2022-05-04T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651734000000 | 2022-05-05T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651762800000 | 2022-05-05T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651791600000 | 2022-05-05T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651820400000 | 2022-05-06T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651849200000 | 2022-05-06T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651878000000 | 2022-05-06T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651906800000 | 2022-05-07T07:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1651935600000 | 2022-05-07T15:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651964400000 | 2022-05-07T23:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1651993200000 | 2022-05-08T07:00:00.000Z
BTC/USDT:USDT |      0.0001 | 1652022000000 | 2022-05-08T15:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652050800000 | 2022-05-08T23:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652079600000 | 2022-05-09T07:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652108400000 | 2022-05-09T15:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652137200000 | 2022-05-09T23:00:00.000Z
BTC/USDT:USDT |   -0.000057 | 1652166000000 | 2022-05-10T07:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652194800000 | 2022-05-10T15:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652223600000 | 2022-05-10T23:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652252400000 | 2022-05-11T07:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652281200000 | 2022-05-11T15:00:00.000Z
BTC/USDT:USDT |     -0.0001 | 1652310000000 | 2022-05-11T23:00:00.000Z
BTC/USDT:USDT |     -0.0003 | 1652338800000 | 2022-05-12T07:00:00.000Z
BTC/USDT:USDT |     -0.0003 | 1652367600000 | 2022-05-12T15:00:00.000Z
BTC/USDT:USDT |     -0.0003 | 1652396400000 | 2022-05-12T23:00:00.000Z
100 objects
```

ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt