csduarte: add main.go for Gophercon!
csduarte: add main.go for Gophercon!

Change-Id: I0154ddc5bad807b8b5cb3a716b27d80d3cab27d0
Reviewed-on: https://go-review.googlesource.com/48907
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/scratch