Added missing license header

Change-Id: I39b55229b63ff377d12956112a4f08c7cbec00ad

buildhelpers/src/com/vaadin/buildhelpers/FetchReleaseNotesTickets.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 2000-2013 Vaadin Ltd.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
 package com.vaadin.buildhelpers;
 
 import java.io.IOException;