Add CONTRIBUTING.md (#7)

* Add CONTRIBUTING.md

* Update CONTRIBUTING.md

* Copied Fluo contrib.md, omitting testing section

CONTRIBUTING.md

@@ -0,0 +1,41 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You 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.
+-->
+
+# Contributing to Fluo Yarn
+
+## Building Fluo Yarn
+
+If you have [Git], [Maven], and [Java][java] (version 8+) installed, run these commands to build
+Fluo Yarn:
+
+    git clone https://github.com/apache/fluo-yarn.git
+    cd fluo-yarn
+    mvn package
+
+## Pull Request
+
+Before making a pull request please attempt to run `mvn verify`.  If it fails and you are not sure 
+why, it's OK to go ahead and make the pull request.
+
+## See Also
+
+* [How to Contribute][contribute] on Apache Fluo project website
+
+[Git]: https://git-scm.com/
+[java]: http://openjdk.java.net/
+[Maven]: https://maven.apache.org/
+[contribute]: https://fluo.apache.org/how-to-contribute/