db drop 추가

mongo.go

@@ -136,6 +136,10 @@ func (mc MongoClient) Close() {
 	}
 }
 
+func (mc MongoClient) Drop() error {
+	return mc.db.Drop(context.Background())
+}
+
 func (mc MongoClient) DropIndex(coll CollectionName, name string) error {
 	matchcoll := mc.Collection(coll)
 	_, err := matchcoll.Indexes().DropOne(context.Background(), name)