add GNU Hurd OS
add GNU Hurd OS

fixes haskell/hackage-server#269

mmakowski/cabal,plow-technologies/cabal,edsko/cabal,christiaanb/cabal,triplepointfive/cabal,sopvop/cabal,bennofs/cabal,lukexi/cabal,rimmington/cabal,valderman/cabal,themoritz/cabal,fugyk/cabal,bennofs/cabal,sopvop/cabal,eric-stanley/cabal,christiaanb/cabal,thoughtpolice/cabal,martinvlk/cabal,thomie/cabal,trskop/cabal,trskop/cabal,anton-dessiatov/cabal,ghc-android/cabal,enolan/cabal,randen/cabal,Peaker/cabal,plow-technologies/cabal,kosmikus/cabal,Helkafen/cabal,enolan/cabal,gbaz/cabal,garetxe/cabal,lukexi/cabal,mightybyte/cabal,x-y-z/cabal,beni55/cabal,x-y-z/cabal,beni55/cabal,Helkafen/cabal,gbaz/cabal,ian-ross/cabal,martinvlk/cabal,mightybyte/cabal,themoritz/cabal,Heather/cabal,thomie/cabal,mmakowski/cabal,seereason/cabal,kolmodin/cabal,ghc-android/cabal,randen/cabal,headprogrammingczar/cabal,eric-stanley/cabal,fugyk/cabal,Peaker/cabal,edsko/cabal,garetxe/cabal,Heather/cabal,corngood/cabal,seereason/cabal,mydaum/cabal,triplepointfive/cabal,anton-dessiatov/cabal,gridaphobe/cabal,valderman/cabal,kolmodin/cabal,kosmikus/cabal,thoughtpolice/cabal,sopvop/cabal,rimmington/cabal,gridaphobe/cabal,themoritz/cabal,mydaum/cabal,corngood/cabal,headprogrammingczar/cabal,ian-ross/cabal