Use revive instead of gometalinter

[enocom]

Although it might not offer as complete coverage, revive seems significantly faster than gometalinter with a simpler API. Switching linters might help resolve the gometalinter timeouts we've been seeing in CI.

[markmandel]

Should we also explore:
https://github.com/golangci/golangci-lint/

And/or maybe move the actual work over to the hosted service they provide as well? (https://golangci.com) ?

[enocom]

I think so, as the timeout failures seems to be common, and it's worth looking at alternatives, even if our linting isn't 100% the same as gometalinter.

[markmandel]

Even at the 5 minute timeout - sometimes it just doesn't timeout (and continues forever), and sometimes it's still hits the deadline.

I've had to restart recent builds several times at this point.