[BEAM-<Jira issue #>] Description of pull request

Be sure to do all of the following to help us incorporate your contribution
quickly and easily:

 - [ ] Make sure tests pass via `mvn clean verify`. (Even better, enable 
       Travis-CI for on your fork and ensure the whole test matrix passes).
 - [ ] Replace "<Jira issue #>" in the title with the actual Jira issue 
       number, if there is one.
 - [ ] If this contribution is large, please file an Apache
       [Individual Contributor License Agreement](https://www.apache.org/licenses/icla.txt).
       

Add GitHub pull request template
Add GitHub pull request template
