Merge pull request #127 from rumpl/add-pull-request-template

Add pull request template

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,8 @@
+**What I did**
+
+**Related issue**
+<-- If this is a bug fix, make sure your description includes "fixes #xxxx", or
+"closes #xxxx"
+-->
+
+**(not mandatory) A picture of a cute animal, if possible in relation with what you did**