tests/html-tests/copy.hs: Use mapM_ instead of mapM
tests/html-tests/copy.hs: Use mapM_ instead of mapM

So we do net get a list of () on stdout when running with runhaskell.

Helkafen/haddock,Helkafen/haddock,Fuuzetsu/haddock,adamse/haddock,JPMoresmau/haddock,Wizek/haddock,randen/haddock,Acidburn0zzz/haddock,mrBliss/haddock,Mistuke/haddock,esmolanka/haddock,esmolanka/haddock,jgm/haddock,haskell/haddock,beni55/haddock,haskell/haddock,JPMoresmau/haddock,adamse/haddock,Acidburn0zzz/haddock,Mistuke/haddock,Mistuke/haddock,adamse/haddock,mrBliss/haddock,Helkafen/haddock,sboosali/haddock,Fuuzetsu/haddock,JPMoresmau/haddock,randen/haddock,mrBliss/haddock,Fuuzetsu/haddock,idontgetoutmuch/haddock,jstolarek/haddock,idontgetoutmuch/haddock,sboosali/haddock,niteria/haddock,beni55/haddock,mrhania/haddock,lamefun/haddock,Wizek/haddock,Fuuzetsu/haddock,esmolanka/haddock,Wizek/haddock,lamefun/haddock,haskell/haddock,niteria/haddock,Acidburn0zzz/haddock,haskell/haddock,beni55/haddock,jgm/haddock,lamefun/haddock,haskell/haddock,randen/haddock,idontgetoutmuch/haddock,niteria/haddock,jstolarek/haddock,mrhania/haddock,mrhania/haddock,sboosali/haddock