small update

joysticklibrary/src/main/java/com/erz/joysticklibrary/JoyStick.java

@@ -1,3 +1,19 @@
+/*
+    Copyright 2015 erz05
+
+    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.erz.joysticklibrary;
 
 import android.content.Context;