Engine QA (#367)

* Improved error message when no config is set on startup

* Change inccorect error wording

* bump Bitfinex websocket orderbook return length to max

* temporary fix of incorrect orderbook updates, limit to bid and ask len of 100, will be extended later if needed

* Fixed issue in binance websocket that appended 0 volume bid/ask items

* Fix panic when unmarshalling an empty pair from config

* Add get pair asset method for exchange base
Fix Bitmex orderbook stream
Unbuffer Bitmex orderbook stream

* force syncer to update ticker instead of fetch, which allows a stream

* Fix websocket last price for coinbasepro

* fix websocket ticker for coinut

* Fix websocket orderbook stream Huobi

* increase orderbook depth REST for Huobi

* Fix websocket support and ensure data integrity

* Fix time parsing issue after error checks

* check error, only process enabled currency pairs, signal websocket data processing

* expanded websocket functionality for okgroup

* Add logic to not process zero length slice for orderbooks

* fix websocket ticker only updating enabled and individual book updates

* ZB fixes to order submission/retrieval/cancellation w/ general fixes

* Quiet unnecessary warning

* updated config entry values for REST and websocket (initial hack until I come up with a better solution for asset types)

* Ch GetName function to field access modifyer & rm useless code

* Add in error I missed

* Nits addressed

* some more fixes

* Turned kraken default websocket to true and some small changes

* fixes linter issues

* Ensured okgroup books and sent update through to datahandler. Zb update as well.

* Add test case to get asset type from pair

* Add test for pairs unmarshal

* Add testing and addressed nits

* FIX linter issue

* Addressed Gees nits

* Thanks glorious spotter

* more nitorinos

* Addres even more nits

* Add stringerino 4000

* Fix for panic cause by sort slice out of range, also nits addressed

* fix linter issues

* Changed from function to field access

* Changed from function to field access

* fix for orderbook update panic, removes quick fix - caused by sync item fetching through same protocol

* Add new test and update random generator

* pass in invalid string to future ob fetching, due to futures contract expire and a http 400 error is returned

exchanges/gemini/gemini_websocket.go

@@ -319,11 +319,11 @@ func (g *Gemini) wsProcessUpdate(result WsMarketUpdateResponse, pair currency.Pa
 			}
 		}
 		err := g.Websocket.Orderbook.Update(&wsorderbook.WebsocketOrderbookUpdate{
-			Asks:         asks,
-			Bids:         bids,
-			CurrencyPair: pair,
-			UpdateTime:   time.Unix(0, result.TimestampMS),
-			AssetType:    asset.Spot,
+			Asks:       asks,
+			Bids:       bids,
+			Pair:       pair,
+			UpdateTime: time.Unix(0, result.TimestampMS),
+			Asset:      asset.Spot,
 		})
 		if err != nil {
 			g.Websocket.DataHandler <- fmt.Errorf("%v %v", g.Name, err)