updated /add_user endpoint to return status code instead of user ob…

…ject (#718)

* Update `/add_user` endpoint to return status code instead of user object
Fixes #707

* removed unessary unique username validation

care/users/api/viewsets/users.py

@@ -161,14 +161,8 @@ def add_user(self, request, *args, **kwargs):
             data={**request.data, "password": password}, context={"created_by": request.user},
         )
         serializer.is_valid(raise_exception=True)
-        username = request.data["username"]
-        if User.objects.filter(username=username).exists():
-            raise ValidationError({"username": "User with Given Username Already Exists"})
-        user = serializer.create(serializer.validated_data)
-
-        response_data = UserCreateSerializer(user).data
-        # response_data["password"] = password
-        return Response(data=response_data, status=status.HTTP_201_CREATED)
+        serializer.save()
+        return Response(status=status.HTTP_201_CREATED)
 
     def has_facility_permission(self, user, facility):
         return (