adamkisala: adding main to Gophercon with licence
adamkisala: adding main to Gophercon with licence

Change-Id: I1915721aa6b76d39a9bebf6553bb8c993a6428a7
Reviewed-on: https://go-review.googlesource.com/48851
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/scratch