fix: gofmt error. (#833)

mode.go

@@ -19,9 +19,9 @@ const (
 	TestMode    string = "test"
 )
 const (
-	debugCode   = iota
-	releaseCode 
-	testCode  
+	debugCode = iota
+	releaseCode
+	testCode
 )
 
 // DefaultWriter is the default io.Writer used the Gin for debug output and