feat: switch from grunt to gulp and use sass

it's about time!
though we should actually be thinking webpack!

Author: engineervix

{{cookiecutter.project_slug}}/.pre-commit-config.yaml

@@ -69,5 +69,6 @@ repos:
         exclude: >
           (?x)^(
               (.*)/static/vendors|
+              (.*)/static/css/main\.css|
               ^.+\.min\.(css)$
           )$