add param

Merge remote-tracking branch 'origin/master'

python spot sdk version 3

GET /v1/order/matchresults,

GET /v1/order/orders/{order-id}/matchresults
优化
新增参数抵扣状态：fee-deduct-state（ 抵扣中：ongoing/ 抵扣完成：done），来代表手续费抵扣中和抵扣完成的状态

Merge pull request #62 from 99Kies/master

del .DS_Store

Update according to API update in May and June

Update version to 2.0.0

Refine GetAccounts and Add two new API for API update in April 2020

v1.0.13: Add order update v2 subscription

Update CHANGE_LOG.md