add the template for pull requests on GitHub

Author: iteman

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,10 @@
+| Q             | A
+| ------------- | ---
+| Branch?       | `master` for new features / `1.1` for fixes
+| Bug fix?      | yes/no
+| New feature?  | yes/no
+| BC breaks?    | yes/no
+| Deprecations? | yes/no
+| Tests pass?   | yes/no
+| Fixed tickets | comma-separated list of tickets fixed by the PR, if any
+| License       | BSD-2-Clause