Merge branch 'Backend-refactoring' into 'master'

backend/secfit/comments/permissions.py

backend/secfit/comments/views.py

backend/secfit/secfit/djangoHeroku.py

backend/secfit/secfit/settings.py

backend/secfit/users/admin.py

backend/secfit/users/serializers.py

backend/secfit/users/tests.py

backend/secfit/users/tests/__init__.py

...nd/secfit/users/tests/__pycache__/__init__.cpython-39.pyc

...ecfit/users/tests/__pycache__/registration.cpython-39.pyc

.../secfit/users/tests/__pycache__/rememberme.cpython-39.pyc

...ecfit/users/tests/__pycache__/twowaydomain.cpython-39.pyc

...fit/users/tests/__pycache__/userserializer.cpython-39.pyc

backend/secfit/users/tests/registration.py

backend/secfit/users/tests/rememberme.py

backend/secfit/users/tests/twowaydomain.py

backend/secfit/users/tests/userserializer.py

backend/secfit/users/views.py

backend/secfit/workouts/serializers.py

backend/secfit/workouts/tests/__init__.py