Add upper bound for yaml, #4053
Add upper bound for yaml, #4053

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