build: don't run lint from test-ci

Since we will run linting before compiling or testing there's no
need to run it as part of the ci testing.

PR-URL: https://github.com/nodejs/io.js/pull/1965


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Revewied-By: Evan Lucas <evanlucas@me.com>