Feature: Add support to check whether an exchange supports automatic currency pair updates and if they don't, show a warning if the last currency pair update is >= 30 days

Also fix race condition in config get/set functions

exchanges/kraken/kraken.go

@@ -63,6 +63,7 @@ func (k *Kraken) SetDefaults() {
 	k.ConfigCurrencyPairFormat.Delimiter = "-"
 	k.ConfigCurrencyPairFormat.Uppercase = true
 	k.AssetTypes = []string{ticker.Spot}
+	k.SupportsAutoPairUpdating = true
 }
 
 // Setup sets current exchange configuration
@@ -87,6 +88,10 @@ func (k *Kraken) Setup(exch config.ExchangeConfig) {
 		if err != nil {
 			log.Fatal(err)
 		}
+		err = k.SetAutoPairDefaults()
+		if err != nil {
+			log.Fatal(err)
+		}
 	}
 }