revert "add gi-gtk-hs, gi-gtksource, gi-webkit2" (fpco/lts-haskell#72)
revert "add gi-gtk-hs, gi-gtksource, gi-webkit2" (fpco/lts-haskell#72)

gi-gio and gi-pango cause ghc to panic

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