Remove reference to "installable perl6" from the Makefile.
Remove reference to "installable perl6" from the Makefile.

dankogai/rakudo,dwarring/rakudo,rakudo/rakudo,Gnouc/rakudo,samcv/rakudo,niner/rakudo,retupmoca/rakudo,softmoth/rakudo,softmoth/rakudo,tony-o/rakudo,b2gills/rakudo,azawawi/rakudo,lucasbuchala/rakudo,cognominal/rakudo,ungrim97/rakudo,Leont/rakudo,zhuomingliang/rakudo,dankogai/rakudo,skids/rakudo,Gnouc/rakudo,skids/rakudo,tbrowder/rakudo,tbrowder/rakudo,softmoth/rakudo,ugexe/rakudo,azawawi/rakudo,rakudo/rakudo,tbrowder/rakudo,sergot/rakudo,zostay/rakudo,tony-o/rakudo,cygx/rakudo,salortiz/rakudo,nbrown/rakudo,salortiz/rakudo,rjbs/rakudo,cognominal/rakudo,lucasbuchala/rakudo,labster/rakudo,teodozjan/rakudo,tony-o/deb-rakudodaily,sergot/rakudo,labster/rakudo,Gnouc/rakudo,sjn/rakudo,sergot/rakudo,tony-o/rakudo,skids/rakudo,ungrim97/rakudo,awwaiid/rakudo,retupmoca/rakudo,jonathanstowe/rakudo,dwarring/rakudo,labster/rakudo,ugexe/rakudo,nbrown/rakudo,nunorc/rakudo,labster/rakudo,awwaiid/rakudo,ab5tract/rakudo,Leont/rakudo,rakudo/rakudo,niner/rakudo,raydiak/rakudo,cygx/rakudo,pmurias/rakudo,softmoth/rakudo,MasterDuke17/rakudo,paultcochrane/rakudo,cognominal/rakudo,usev6/rakudo,paultcochrane/rakudo,LLFourn/rakudo,mrgetit/rakudo,paultcochrane/rakudo,tbrowder/rakudo,jonathanstowe/rakudo,tony-o/deb-rakudodaily,usev6/rakudo,dakkar/rakudo,salortiz/rakudo,nbrown/rakudo,azawawi/rakudo,raydiak/rakudo,pmurias/rakudo,ugexe/rakudo,nbrown/rakudo,paultcochrane/rakudo,Gnouc/rakudo,dwarring/rakudo,ungrim97/rakudo,sjn/rakudo,LLFourn/rakudo,lucasbuchala/rakudo,ab5tract/rakudo,LLFourn/rakudo,zhuomingliang/rakudo,dankogai/rakudo,sjn/rakudo,pmurias/rakudo,tony-o/deb-rakudodaily,cygx/rakudo,zhuomingliang/rakudo,cognominal/rakudo,jonathanstowe/rakudo,samcv/rakudo,sergot/rakudo,salortiz/rakudo,tbrowder/rakudo,teodozjan/rakudo,ungrim97/rakudo,rjbs/rakudo,retupmoca/rakudo,lucasbuchala/rakudo,salortiz/rakudo,tony-o/rakudo,rakudo/rakudo,ungrim97/rakudo,tony-o/deb-rakudodaily,teodozjan/rakudo,tony-o/rakudo,tony-o/rakudo,laben/rakudo,usev6/rakudo,dankogai/rakudo,MasterDuke17/rakudo,rjbs/rakudo,softmoth/rakudo,MasterDuke17/rakudo,dankogai/rakudo,cognominal/rakudo,zostay/rakudo,zostay/rakudo,lucasbuchala/rakudo,zostay/rakudo,labster/rakudo,tony-o/deb-rakudodaily,b2gills/rakudo,awwaiid/rakudo,LLFourn/rakudo,tbrowder/rakudo,Leont/rakudo,usev6/rakudo,tony-o/deb-rakudodaily,nunorc/rakudo,laben/rakudo,b2gills/rakudo,rakudo/rakudo,b2gills/rakudo,awwaiid/rakudo,paultcochrane/rakudo,jonathanstowe/rakudo,zhuomingliang/rakudo,labster/rakudo,Gnouc/rakudo,azawawi/rakudo,ab5tract/rakudo,skids/rakudo,tony-o/deb-rakudodaily,raydiak/rakudo,nunorc/rakudo,samcv/rakudo,sjn/rakudo,ugexe/rakudo,ab5tract/rakudo,rakudo/rakudo,usev6/rakudo,niner/rakudo,b2gills/rakudo,niner/rakudo,pmurias/rakudo,nunorc/rakudo,Gnouc/rakudo,ab5tract/rakudo,laben/rakudo,salortiz/rakudo,samcv/rakudo,azawawi/rakudo,teodozjan/rakudo,Leont/rakudo,LLFourn/rakudo,jonathanstowe/rakudo,nbrown/rakudo,nbrown/rakudo,retupmoca/rakudo,raydiak/rakudo,cygx/rakudo,MasterDuke17/rakudo,dwarring/rakudo,cygx/rakudo,awwaiid/rakudo,ugexe/rakudo,MasterDuke17/rakudo,skids/rakudo,sjn/rakudo,samcv/rakudo,MasterDuke17/rakudo,laben/rakudo