fix test layer ordering

CHANGES.rst

@@ -45,6 +45,9 @@ Bug fixes:
 
 - Remove unittest2 dependency
   [kakshay21]
+- Make sure the effects of the robotframework REMOTE_LIBRARY_ROBOT_TESTING fixture
+  are not accidentally removed when tearing down the PLONE_APP_DISCUSSION_ROBOT_TESTING fixture.
+  [davisagli]
 
 
 3.0.0 (2017-02-12)

plone/app/discussion/testing.py

@@ -98,6 +98,11 @@ class PloneAppDiscussion(PloneSandboxLayer):
 
 class PloneAppDiscussionRobot(PloneAppDiscussion):
 
+    defaultBases = (
+        PLONE_APP_CONTENTTYPES_FIXTURE,
+        REMOTE_LIBRARY_ROBOT_TESTING,
+    )
+
     def setUpPloneSite(self, portal):
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings)
@@ -113,9 +118,6 @@ PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING = FunctionalTesting(
     bases=(PLONE_APP_DISCUSSION_FIXTURE,),
     name='PloneAppDiscussion:Functional')
 PLONE_APP_DISCUSSION_ROBOT_TESTING = FunctionalTesting(
-    bases=(
-        PLONE_APP_DISCUSSION_ROBOT_FIXTURE,
-        REMOTE_LIBRARY_ROBOT_TESTING
-    ),
+    bases=(PLONE_APP_DISCUSSION_ROBOT_FIXTURE,),
     name='PloneAppDiscussion:Robot'
 )