fix gofmt for go 1.12

registry_test.go

@@ -379,7 +379,7 @@ func TestConcurrentRegistryAccess(t *testing.T) {
 }
 
 // exercise race detector
-func TestRegisterAndRegisteredConcurrency(t *testing.T)  {
+func TestRegisterAndRegisteredConcurrency(t *testing.T) {
 	r := NewRegistry()
 	wg := &sync.WaitGroup{}
 	wg.Add(1)
@@ -390,4 +390,4 @@ func TestRegisterAndRegisteredConcurrency(t *testing.T)  {
 	}(r, wg)
 	r.Register("foo", NewCounter())
 	wg.Wait()
-}
+}