Remove pipes-cliff
Remove pipes-cliff

Is unmaintained and may be buggy.  Has no dependencies in Stackage.

Shimuuar/stackage,lwm/stackage,DanielG/stackage,ygale/stackage,mgajda/stackage,soenkehahn/stackage,fimad/stackage,peti/stackage,massysett/stackage,athanclark/stackage,simonmichael/stackage,judah/stackage,Daniel-Diaz/stackage,mstksg/stackage,GregorySchwartz/stackage,michalkonecny/stackage,fpco/stackage,phadej/stackage,garetxe/stackage,creichert/stackage,k0ral/stackage,wereHamster/stackage,clinty/stackage,alanz/stackage,stackbuilders/stackage,jonschoning/stackage,mrkkrp/stackage,christiaanb/stackage,int-index/stackage,phaazon/stackage,iand675/stackage,jaspervdj/stackage,ethercrow/stackage,asr/stackage,spencerjanssen/stackage,brendanhay/stackage