core: make is_superuser a group property, remove from user

passbook/core/api/groups.py

@@ -11,7 +11,7 @@ class GroupSerializer(ModelSerializer):
     class Meta:
 
         model = Group
-        fields = ["pk", "name", "parent", "user_set", "attributes"]
+        fields = ["pk", "name", "is_superuser", "parent", "users", "attributes"]
 
 
 class GroupViewSet(ModelViewSet):

passbook/core/api/users.py

@@ -1,5 +1,5 @@
 """User API Views"""
-from rest_framework.serializers import ModelSerializer
+from rest_framework.serializers import BooleanField, ModelSerializer
 from rest_framework.viewsets import ModelViewSet
 
 from passbook.core.models import User
@@ -8,10 +8,12 @@ from passbook.core.models import User
 class UserSerializer(ModelSerializer):
     """User Serializer"""
 
+    is_superuser = BooleanField(read_only=True)
+
     class Meta:
 
         model = User
-        fields = ["pk", "username", "name", "email"]
+        fields = ["pk", "username", "name", "is_superuser", "email"]
 
 
 class UserViewSet(ModelViewSet):