brew: Add brew bin dir to PATH
brew: Add brew bin dir to PATH

If a brewed Ruby is used, user MUST set PATH. That may cause odd errors,
so always prepend brewed binrary dir to PATH.

SuperNEMO-DBD/cadfaelbrew,SuperNEMO-DBD/cadfaelbrew,SuperNEMO-DBD/cadfaelbrew,SuperNEMO-DBD/cadfaelbrew