[REFACTOR] change django apps structure

sizakat/apps/mustahik/migrations/__init__.py

sizakat/mustahik/__init__.py

sizakat/mustahik/admin.py

sizakat/mustahik/apps.py

sizakat/mustahik/models.py

sizakat/mustahik/mutations.py

sizakat/mustahik/query.py

sizakat/mustahik/tests.py

sizakat/mustahik/types.py

sizakat/schema.py

sizakat/settings.py