style: Resolve all pep8/pylint complaints

manage.py

@@ -7,6 +7,7 @@ import sys
 def main():
     os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'breccia_mapper.settings')
     try:
+        # pylint: disable=import-outside-toplevel
         from django.core.management import execute_from_command_line
     except ImportError as exc:
         raise ImportError(