martisch: add main.go for Gophercon
martisch: add main.go for Gophercon

Change-Id: Ibe782f37fdf70290b9d8dea24ddda2c2e6a77bc5
Reviewed-on: https://go-review.googlesource.com/48855
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/scratch