Django 1.8 fails with an ImproperlyConfigured exception when `fields`
or `exclude` isn't set:

```
class Meta:
 fields = '__all__'
```

on all descendents of ModelForm.

Omitting this is deprecated in 1.7:

https://docs.djangoproject.com/en/1.7/topics/forms/modelforms/#selecting-the-fields-to-use

Change-Id: I68dd6b8c67a1590f18d4924512319bb32272aa5a
diff --git a/xos/admin.py b/xos/admin.py
index fb0f1d7..f7347ae 100644
--- a/xos/admin.py
+++ b/xos/admin.py
@@ -45,6 +45,7 @@
 
     class Meta:
         model = ONOSService
+        fields = '__all__'
 
 class ONOSServiceAdmin(ReadOnlyAwareAdmin):
     model = ONOSService
@@ -103,6 +104,7 @@
 
     class Meta:
         model = ONOSApp
+        fields = '__all__'
 
 class ONOSAppAdmin(ReadOnlyAwareAdmin):
     list_display = ('backend_status_icon', 'name', )