Add artist search in card command

src/serra/card.go

@@ -10,6 +10,7 @@ import (
 )
 
 func init() {
+	cardCmd.Flags().StringVarP(&artist, "artist", "a", "", "Filter by name of artist")
 	cardCmd.Flags().StringVarP(&rarity, "rarity", "r", "", "Filter by rarity of cards (mythic, rare, uncommon, common)")
 	cardCmd.Flags().StringVarP(&set, "set", "e", "", "Filter by set code (usg/mmq/vow)")
 	cardCmd.Flags().StringVarP(&sortby, "sort", "s", "name", "How to sort cards (value/number/name/added)")
@@ -106,6 +107,10 @@ func Cards(rarity, set, sortby, name, oracle, cardType string, reserved, foil bo
 		filter = append(filter, bson.E{"name", bson.D{{"$regex", ".*" + name + ".*"}, {"$options", "i"}}})
 	}
 
+	if len(artist) > 0 {
+		filter = append(filter, bson.E{"artist", bson.D{{"$regex", ".*" + artist + ".*"}, {"$options", "i"}}})
+	}
+
 	if cmc > -1 {
 		filter = append(filter, bson.E{"cmc", cmc})
 	}

src/serra/root.go

@@ -7,6 +7,7 @@ import (
 var (
 	Version         = "unknown"
 	address         string
+	artist          string
 	cardType        string
 	color           string
 	cmc             int64