devapp: update Dockerfile.0
devapp: update Dockerfile.0

Change-Id: Ic0e9317afe48c5feb91de43a3b4fb25279a41d47
Reviewed-on: https://go-review.googlesource.com/48597
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/build,golang/build,golang/build,golang/build