Add constraint "free < 5.1" per #3794
Add constraint "free < 5.1" per #3794

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