Add golint to the Dockerfile, and a `validate-lint` task to the
Makefile. Currently, the linter will process a harcoded list of packages
that will expand as we fix more warnings. Eventually, the linter should
process all subpackages of the repo (excluding vendored code).
Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
Arnaud Porterie