Update README.md

Author: mikemccabe

README.md

@@ -27,3 +27,21 @@ Credits
 
 The seed test set was adapted from https://github.com/bruth/jsonpatch-js/blob/master/test.js .
 
+
+License
+-------
+
+ Copyright 2012 Michael McCabe
+ 
+   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.
+