cmd/present: skip the "golang.org" directory
cmd/present: skip the "golang.org" directory

Change-Id: I732194c22062c77c431dcec57f9ef832f1dc1afe
Signed-off-by: Shenghou Ma <72d850dbd8858b791995463d8539b5a379577f28@golang.org>
Reviewed-on: https://go-review.googlesource.com/1512
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

springning/tools,dmitris/tools,magiccao/tools,glasser/golang-tools,syreclabs/go-tools,nicot/tools,cw2018/tools,dmitris/tools,nicot/tools,dmitris/tools,glasser/golang-tools,cmars/tools,cw2018/tools,josharian/tools,4ad/tools,josharian/tools,golang/tools,glasser/golang-tools,maddyonline/tools,4ad/tools,glasser/golang-tools,cmars/tools,jdhenke/tools,sshetty10/tools,argandas/tools,cmars/tools,cw2018/tools,jdhenke/tools,syreclabs/go-tools,syreclabs/go-tools,matryer/tools,golang/tools,springning/tools,matryer/tools,runcom/tools,maddyonline/tools,josharian/tools,syreclabs/go-tools,matryer/tools,sshetty10/tools,golang/tools,runcom/tools,sshetty10/tools,springning/tools,josharian/tools,4ad/tools,matryer/tools,magiccao/tools,dmitris/tools,magiccao/tools,maddyonline/tools,syreclabs/go-tools,jdhenke/tools,argandas/tools,runcom/tools,argandas/tools,jdhenke/tools,golang/tools,cmars/tools,runcom/tools,nicot/tools,maddyonline/tools,syreclabs/go-tools,golang/tools,argandas/tools,sshetty10/tools,nicot/tools,cw2018/tools,springning/tools,magiccao/tools