Add plone.app.customerize to plone_app_testing alltests group and remove plone.subrequest. It seems that plone.subrequest has test isolation issues (needs to be confirmed though).
Upgrade robotsuite to latest 1.6.0 and set ROBOTSUITE_APPEND_OUTPUT_XML to 1.
Merge branch '5.0' of github.com:plone/buildout.coredev into 5.0