Update README.md

Author: DingMouRen

README.md

@@ -26,5 +26,20 @@ PaletteImageView可以动态的提取图片的主要颜色，并将颜色作为
 
 欢迎大家提Issues.
 
+## License
+```
+Copyright (C) 2017 WeyYe
+
+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
+```