ci: enable go static checkers

[grahamwhaley]

As far as I can tell we are not running any of the go static checkers on this repo. It doesn't look like we invoke them from our .ci or that they are invoked from the clearcontainers/tests scrips we invoke either. I also checked the Travis logs and could see no evidence.
We should probably start by importing the go-static-checks.sh script once we have a nicely fixed up version - see clearcontainers/tests#110 for more info.

btw, currently the repo seems to be showing no problems from a hand run of the static checkers - take a bow the relevant developers :-)

[grahamwhaley]

I note, houndci that we use on this repo uses golint for checking go code already - so we could drop that from the go-static-checks script if we need, but the overheads are probably small enough to just leave it be unless it becomes an issue.