Add license header to EventCollectingHandler

Author: barnardb

api/src/test/java/org/asynchttpclient/async/util/EventCollectingHandler.java

@@ -1,3 +1,15 @@
+/*
+ * Copyright (c) 2014 AsyncHttpClient Project. All rights reserved.
+ *
+ * This program is licensed to you under the Apache License Version 2.0,
+ * and you may not use this file except in compliance with the Apache License Version 2.0.
+ * You may obtain a copy of the Apache License Version 2.0 at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the Apache License Version 2.0 is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
+ */
 package org.asynchttpclient.async.util;
 
 import org.asynchttpclient.AsyncCompletionHandlerBase;