Ignore environment variables for coffeelint

Summary: According to `coffeelint --help`, `--noconfig` ignores the environment variable `COFFEELINT_CONFIG`. This means that `arc lint` will behave more consistently across developer workstations by forcing configuration to be specified with `coffeelint.config` instead of with environment variables.

Test Plan: This is mostly theoretical.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11196

src/lint/linter/ArcanistCoffeeLintLinter.php

@@ -61,6 +61,7 @@ final class ArcanistCoffeeLintLinter extends ArcanistExternalLinter {
     $options = array(
       '--reporter=checkstyle',
       '--color=never',
+      '--noconfig',
       '--quiet',
     );