Add a pull request template (#31)

Author: maschwenk

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,10 @@
+# Description
+
+Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context.
+
+# Checklist:
+
+- [ ] I have made corresponding changes to the documentation
+- [ ] I have added tests that prove my fix is effective or that my feature works
+- [ ] I have added entries to `CHANGELOG.md` and marked it Added/Changed/Removed
+- [ ] I have not incremented `version.rb`