Bitmex: Fix UpdateTicker/UpdateOrderbook wrappers

UpdateTicker: drop need for start timestamp as the latest entry will always be returned by default
UpdateOrderbook: fix string comparison so that orderbook entries will actually be appended

NOTE: As of this time, Bitmex doesn't support a ticker API endpoint so the only two options are a) last trade for an asset (which GCT uses) or b) orderbook data query
Fixes issue: https://github.com/thrasher-/gocryptotrader/issues/282

exchanges/bitmex/bitmex_wrapper.go

@@ -4,8 +4,8 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"strings"
 	"sync"
-	"time"
 
 	"github.com/thrasher-/gocryptotrader/common"
 	"github.com/thrasher-/gocryptotrader/currency"
@@ -61,10 +61,9 @@ func (b *Bitmex) UpdateTicker(p currency.Pair, assetType string) (ticker.Price,
 	currency := exchange.FormatExchangeCurrency(b.Name, p)
 
 	tick, err := b.GetTrade(&GenericRequestParams{
-		Symbol:    currency.String(),
-		StartTime: time.Now().Format(time.RFC3339),
-		Reverse:   true,
-		Count:     1})
+		Symbol:  currency.String(),
+		Reverse: true,
+		Count:   1})
 	if err != nil {
 		return tickerPrice, err
 	}
@@ -109,12 +108,12 @@ func (b *Bitmex) UpdateOrderbook(p currency.Pair, assetType string) (orderbook.B
 	}
 
 	for _, ob := range orderbookNew {
-		if ob.Side == exchange.SellOrderSide.ToString() {
+		if strings.ToUpper(ob.Side) == exchange.SellOrderSide.ToString() {
 			orderBook.Asks = append(orderBook.Asks,
 				orderbook.Item{Amount: float64(ob.Size), Price: ob.Price})
 			continue
 		}
-		if ob.Side == exchange.BuyOrderSide.ToString() {
+		if strings.ToUpper(ob.Side) == exchange.BuyOrderSide.ToString() {
 			orderBook.Bids = append(orderBook.Bids,
 				orderbook.Item{Amount: float64(ob.Size), Price: ob.Price})
 			continue