Remove legacy checklist steps from PR template (#159)

Author: manzt

.github/PULL_REQUEST_TEMPLATE.md

@@ -9,7 +9,5 @@ Fixes #___
 ## Checklist
 
 - [ ] Unit tests added or updated
-- [ ] Update `examples.ipynb` notebook
 - [ ] Documentation added or updated
 - [ ] Updated CHANGELOG.md
-- [ ] Ran `black` on the root directory