Rename class role to group role

aleksis/apps/alsijil/forms.py

aleksis/apps/alsijil/menus.py

aleksis/apps/alsijil/migrations/0009_group_roles.py

aleksis/apps/alsijil/models.py

aleksis/apps/alsijil/preferences.py

aleksis/apps/alsijil/rules.py

aleksis/apps/alsijil/tables.py

...sis/apps/alsijil/templates/alsijil/group_role/create.html

aleksis/apps/alsijil/templates/alsijil/group_role/edit.html

aleksis/apps/alsijil/templates/alsijil/group_role/list.html

...is/apps/alsijil/templates/alsijil/group_role/warning.html

aleksis/apps/alsijil/urls.py

aleksis/apps/alsijil/views.py