Update README.md

Author: marcoscgdev

README.md

@@ -94,3 +94,21 @@ Custom dialog strings (just override it):
 >See the *sample project* to clarify any queries you may have.
 
 ---
+
+## License
+
+```
+Copyright 2017 Marcos Calvo García
+
+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.
+```