Added a PR template (#56)

Enact-DCO-1.0-Signed-off-by: Mikyung Kim (mikyung27.kim@lge.com)

Author: MikyungKim

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,29 @@
+### Checklist
+
+* [ ] I have read and understand the [contribution guide](http://enactjs.com/docs/developer-guide/contributing/)
+* [ ] A [CHANGELOG entry](http://enactjs.com/docs/developer-guide/contributing/changelogs/) is included
+* [ ] At least one test case is included for this feature or bug fix
+* [ ] I have run automated CLI testing and it is passed
+* [ ] Documentation was added or is not needed
+* [ ] This is an API breaking change
+
+### Issue Resolved / Feature Added
+[//]: # (Describe the issue resolved or feature added by this pull request)
+
+
+### Resolution
+[//]: # (Does the code work as intended?)
+[//]: # (What is the impact of this change and *why* was it made?)
+
+
+### Additional Considerations
+[//]: # (How should the change be tested?)
+[//]: # (Are there any outstanding questions?)
+[//]: # (Were any side-effects caused by the change?)
+
+
+### Links
+[//]: # (Related issues, references)
+
+
+### Comments