add a pull request template (BlueBrain#342)

* add a pull request template

* update PR template

* pr template break long sentence into 2

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,14 @@
+
+# Pull Request Template
+
+## Description
+
+Please include a summary of the change.
+By default the change will increment the patch version.
+To increment major or minor changes add #major or #minor to the PR description.
+
+
+## Checklist:
+- [ ] Unit tests are added to cover the changes.
+- [ ] The changes are mentioned in the documentation.
+- [ ] CHANGELOG.md is updated (skip if the change is not important for the changelog).