Remove yesod-core from expected test failures
Remove yesod-core from expected test failures

See https://github.com/yesodweb/wai/pull/654#issuecomment-346288807

clinty/stackage,peti/stackage,stackbuilders/stackage,wereHamster/stackage,phaazon/stackage,k0ral/stackage,creichert/stackage,simonmichael/stackage,athanclark/stackage,garetxe/stackage,michalkonecny/stackage,fimad/stackage,jonschoning/stackage,int-index/stackage,mstksg/stackage,ethercrow/stackage,asr/stackage,iand675/stackage,fpco/stackage,massysett/stackage,soenkehahn/stackage,Shimuuar/stackage,lwm/stackage,mgajda/stackage,spencerjanssen/stackage,mrkkrp/stackage,Daniel-Diaz/stackage