alter BuildQuery to handle slices
diff --git a/params.go b/params.go
index 509a7c7..4d0f1e6 100644
--- a/params.go
+++ b/params.go
@@ -145,8 +145,12 @@
 					case reflect.Bool:
 						params.Add(tags[0], strconv.FormatBool(v.Bool()))
 					case reflect.Slice:
-						switch f.Type {
-						case reflect.TypeOf([]string{}):
+						switch v.Type().Elem() {
+						case reflect.TypeOf(0):
+							for i := 0; i < v.Len(); i++ {
+								params.Add(tags[0], strconv.FormatInt(v.Index(i).Int(), 10))
+							}
+						default:
 							for i := 0; i < v.Len(); i++ {
 								params.Add(tags[0], v.Index(i).String())
 							}