Fix content type

context/output.go

@@ -206,7 +206,7 @@ func (output *BeegoOutput) JSON(data interface{}, hasIndent bool, encoding bool)
 
 // YAML writes yaml to response body.
 func (output *BeegoOutput) YAML(data interface{}) error {
-	output.Header("Content-Type", "application/application/x-yaml; charset=utf-8")
+	output.Header("Content-Type", "application/x-yaml; charset=utf-8")
 	var content []byte
 	var err error
 	content, err = yaml.Marshal(data)