check file: urls for directory-ness in advance, rather than catching IOError
check file: urls for directory-ness in advance, rather than catching IOError

zorosteven/pip,jasonkying/pip,xavfernandez/pip,caosmo/pip,jamezpolley/pip,habnabit/pip,wkeyword/pip,radiosilence/pip,davidovich/pip,graingert/pip,KarelJakubec/pip,techtonik/pip,chaoallsome/pip,ianw/pip,haridsv/pip,sigmavirus24/pip,blarghmatey/pip,pfmoore/pip,erikrose/pip,graingert/pip,squidsoup/pip,KarelJakubec/pip,RonnyPfannschmidt/pip,alquerci/pip,pypa/pip,James-Firth/pip,jmagnusson/pip,benesch/pip,mattrobenolt/pip,zvezdan/pip,davidovich/pip,pjdelport/pip,qwcode/pip,tdsmith/pip,natefoo/pip,luzfcb/pip,cjerdonek/pip,RonnyPfannschmidt/pip,rbtcollins/pip,patricklaw/pip,yati-sagade/pip,Carreau/pip,mujiansu/pip,jythontools/pip,benesch/pip,pjdelport/pip,esc/pip,xavfernandez/pip,supriyantomaftuh/pip,supriyantomaftuh/pip,sbidoul/pip,James-Firth/pip,alquerci/pip,squidsoup/pip,blarghmatey/pip,cjerdonek/pip,xavfernandez/pip,prasaianooz/pip,jamezpolley/pip,chaoallsome/pip,erikrose/pip,jasonkying/pip,zorosteven/pip,atdaemon/pip,James-Firth/pip,zorosteven/pip,luzfcb/pip,mindw/pip,nthall/pip,caosmo/pip,Carreau/pip,zvezdan/pip,RonnyPfannschmidt/pip,atdaemon/pip,pradyunsg/pip,pjdelport/pip,qbdsoft/pip,benesch/pip,habnabit/pip,qbdsoft/pip,rouge8/pip,rouge8/pip,supriyantomaftuh/pip,jmagnusson/pip,habnabit/pip,Gabriel439/pip,techtonik/pip,ChristopherHogan/pip,nthall/pip,pfmoore/pip,techtonik/pip,Ivoz/pip,dstufft/pip,yati-sagade/pip,qwcode/pip,sbidoul/pip,minrk/pip,h4ck3rm1k3/pip,sigmavirus24/pip,luzfcb/pip,ianw/pip,ncoghlan/pip,rouge8/pip,mindw/pip,dstufft/pip,erikrose/pip,prasaianooz/pip,yati-sagade/pip,alex/pip,rbtcollins/pip,jmagnusson/pip,willingc/pip,nthall/pip,minrk/pip,jasonkying/pip,Gabriel439/pip,tdsmith/pip,fiber-space/pip,haridsv/pip,squidsoup/pip,jythontools/pip,ChristopherHogan/pip,willingc/pip,jythontools/pip,mujiansu/pip,harrisonfeng/pip,pradyunsg/pip,mujiansu/pip,alex/pip,Gabriel439/pip,mindw/pip,alex/pip,sigmavirus24/pip,dstufft/pip,prasaianooz/pip,zenlambda/pip,msabramo/pip,zenlambda/pip,wkeyword/pip,fiber-space/pip,davidovich/pip,caosmo/pip,ncoghlan/pip,pypa/pip,patricklaw/pip,esc/pip,ncoghlan/pip,msabramo/pip,ChristopherHogan/pip,atdaemon/pip,qbdsoft/pip,jamezpolley/pip,wkeyword/pip,natefoo/pip,h4ck3rm1k3/pip,harrisonfeng/pip,h4ck3rm1k3/pip,blarghmatey/pip,esc/pip,mattrobenolt/pip,rbtcollins/pip,fiber-space/pip,haridsv/pip,Ivoz/pip,graingert/pip,KarelJakubec/pip,natefoo/pip,harrisonfeng/pip,willingc/pip,tdsmith/pip,domenkozar/pip,chaoallsome/pip,zvezdan/pip,zenlambda/pip