Update LICENSE.md and CONTRIBUTING.md

Author: kevinsawicki

CONTRIBUTING.md

@@ -1,2 +1 @@
-See [here](https://github.com/atom/atom/blob/master/CONTRIBUTING.md) for the
-contributing guidelines.
+See the [Atom contributing guide](https://atom.io/docs/latest/contributing)

LICENSE.md

@@ -1,13 +1,20 @@
-Copyright 2013 GitHub Inc.
+Copyright (c) 2014 GitHub Inc.
 
-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
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
 
-    http://www.apache.org/licenses/LICENSE-2.0
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
 
-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.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package.json

@@ -4,6 +4,7 @@
   "main": "./lib/git-diff",
   "description": "Add decorations to the editor gutter for lines added, edited, and deleted since the last commit.",
   "repository": "https://github.com/atom/git-diff",
+  "license": "MIT",
   "engines": {
     "atom": "*"
   },