Add the skip-var library
Add the skip-var library

[skip-var](http://hackage.haskell.org/package/skip-var-0.1.0.0)
soenkehahn/stackage,jonschoning/stackage,iand675/stackage,int-index/stackage,stackbuilders/stackage,peti/stackage,ethercrow/stackage,spencerjanssen/stackage,michalkonecny/stackage,mstksg/stackage,fpco/stackage,wereHamster/stackage,Daniel-Diaz/stackage,simonmichael/stackage,asr/stackage,athanclark/stackage,massysett/stackage,mrkkrp/stackage,fimad/stackage,clinty/stackage