New version: v0.1.7

upgrade mongodb client

1. Add Coinsuper Premium; 2. Publish OrderEvent; 3. Upgrade MongoDB c…

…lient;

Add Gate.io & Kraken trade module

Fix bug: order callback filter by symbol.

fix bug: order & position callback should be use copy.copy() to avoid…

… modified.

add Coinsuper Trade module

add okex margin & event center upgrade

add Trade module callbacks: asset_update_callback & init_success_call…

…back

add Huobi module