calvn: add main.go for Gophercon

Change-Id: I65e183ac49cb4544a2fcffefe7670583c0f43e6b
Reviewed-on: https://go-review.googlesource.com/48774
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Chris Broadfoot <cbro@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1 file changed