Services can have their settings defined in-model

sso/evolutions/__init__.py

@@ -1 +1 @@
-SEQUENCE = ['uid_fix']
+SEQUENCE = ['uid_fix', 'settings_json']

sso/evolutions/settings_json.py

@@ -0,0 +1,10 @@
+#----- Evolution for sso
+from django_evolution.mutations import *
+from django.db import models
+from django_jsonfield.fields import JSONField
+
+MUTATIONS = [
+    AddField('Service', 'settings_json', JSONField, initial='{}'),
+]
+#----------------------
+