Update PR template with task list for testing and documentation (#762)

* Update PR template with task list for testing and documentation

* Add README item, make task items more Teutonic

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,6 +1,20 @@
-*Issue #, if available:*
+**Issue #, if available**:
 
-*Description of changes:*
+**Description of changes**:
 
+----
+Enter `[N/A]` in the box, if an item is not applicable to your change.
+
+**Testing**  
+- [ ] Unit tests passed
+- [ ] Integration tests passed
+- [ ] Unit tests added for new functionality
+- [ ] Listed manual checks and their outputs in the comments ([example](https://github.com/aws/amazon-ecs-cli/pull/750#issuecomment-472623042))
+- [ ] Link to issue or PR for the integration tests: 
+
+**Documentation**  
+- [ ] Contacted our doc writer
+- [ ] Updated our README
+----
 
 By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.