lint: fix linter errors from new golang linter
lint: fix linter errors from new golang linter

gometalinter is deprecated and will be archived April '19. The
suggestion is to switch to golangci-lint which is apparently 5x faster
than gometalinter.

Fixes #152

Signed-off-by: Ganesh Maharaj Mahalingam <e84b6eb1374b2034268ad16b797fbec9318eafab@intel.com>

amshinde/shim,amshinde/shim