update comment (#1057)

render/data.go

@@ -11,7 +11,7 @@ type Data struct {
 	Data        []byte
 }
 
-// Render (Data) writes data with custom ContentType
+// Render (Data) writes data with custom ContentType.
 func (r Data) Render(w http.ResponseWriter) (err error) {
 	r.WriteContentType(w)
 	_, err = w.Write(r.Data)