Folder: Add option to force delete folder

grafana/terraform-provider-grafana#855

Author: julienduchesne

folder.go

@@ -112,7 +112,20 @@ func (c *Client) UpdateFolder(uid string, title string, newUID ...string) error
 	return c.request("PUT", fmt.Sprintf("/api/folders/%s", uid), nil, bytes.NewBuffer(data), nil)
 }
 
+func ForceDeleteFolderRules() url.Values {
+	query := make(url.Values)
+	query.Set("forceDeleteRules", "true")
+	return query
+}
+
 // DeleteFolder deletes the folder whose ID it's passed.
-func (c *Client) DeleteFolder(id string) error {
-	return c.request("DELETE", fmt.Sprintf("/api/folders/%s", id), nil, nil, nil)
+func (c *Client) DeleteFolder(id string, optionalQuery ...url.Values) error {
+	var query url.Values
+	if len(optionalQuery) > 1 {
+		return fmt.Errorf("too many arguments. Expected 1 or 2")
+	} else if len(optionalQuery) == 1 {
+		query = optionalQuery[0]
+	}
+
+	return c.request("DELETE", fmt.Sprintf("/api/folders/%s", id), query, nil, nil)
 }