Upgrade GitHub PR template
-* **What kind of change does this PR introduce?** (Bug fix, feature, docs update, ...)
+* **What kind of change does this PR introduce?**
+ - [ ] bug fix
+ - [ ] feature
+ - [ ] docs update
+ - [ ] tests/coverage improvement
+ - [ ] refactoring
+ - [ ] other
* **Other information**:
+
+
+* **Checklist**:
+
+ - [ ] I think the code is well written
+ - [ ] I wrote [good commit messages][1]
+ - [ ] I have [squashed related commits together][2] after the changes have been approved
+ - [ ] Unit tests for the changes exist
+ - [ ] Integration tests for the changes exist (if applicable)
+ - [ ] I used the same coding conventions as the rest of the project
+ - [ ] The new code doesn't generate linter offenses
+ - [ ] Documentation reflects the changes
+ - [ ] The PR relates to *only* one subject with a clear title
+ and description in grammatically correct, complete sentences
+
+[1]: http://chris.beams.io/posts/git-commit/
+[2]: https://github.com/todotxt/todo.txt-android/wiki/Squash-All-Commits-Related-to-a-Single-Issue-into-a-Single-Commit
