golangci-lint/CI: Bump versions and introduce new linters (#798)

* golangci-lint/CI: Bump versions

Fix remaining linter issues

* Specifically set AppVeyor version

* Fix the infamous typos 👀

* Add go env cmd to AppVeyor

* Add go version cmd to AppVeyor

* Specify AppVeyor image, adjust linters

* Update go get to go install due to deprecation

* Bump golangci-lint timeout time for AppVeyor

* Change NW contract to NQ

* Address nitters

* GetRandomPair -> Pair{}

* Address nits

* Address time nitterinos plus additional tweaks

* More time inception upgrades!

* Bending time and space

exchanges/exchange.go

@@ -409,7 +409,7 @@ func (b *Base) GetPairFormat(assetType asset.Item, requestFormat bool) (currency
 func (b *Base) GetEnabledPairs(a asset.Item) (currency.Pairs, error) {
 	err := b.CurrencyPairs.IsAssetEnabled(a)
 	if err != nil {
-		return nil, nil
+		return nil, nil // nolint:nilerr // non-fatal error
 	}
 	format, err := b.GetPairFormat(a, false)
 	if err != nil {
@@ -1156,7 +1156,7 @@ func (b *Base) FormatExchangeKlineInterval(in kline.Interval) string {
 // ValidateKline confirms that the requested pair, asset & interval are supported and/or enabled by the requested exchange
 func (b *Base) ValidateKline(pair currency.Pair, a asset.Item, interval kline.Interval) error {
 	var errorList []string
-	var err kline.ErrorKline
+	var err kline.Error
 	if b.CurrencyPairs.IsAssetEnabled(a) != nil {
 		err.Asset = a
 		errorList = append(errorList, "asset not enabled")
@@ -1242,7 +1242,7 @@ func (e *Endpoints) SetRunning(key, val string) error {
 			key,
 			val,
 			e.Exchange)
-		return nil
+		return nil // nolint:nilerr // non-fatal error as we won't update the running URL
 	}
 	e.defaults[key] = val
 	return nil