Basically similar to `ember-cli-eslint`, you get both a warning in the console and a failing test. Links: * https://github.com/ember-cli/ember-cli-eslint/blob/master/index.js#L67-L75 - passing in a custom console that uses `this.ui.writeLine` * https://github.com/ember-cli/broccoli-lint-eslint/blob/master/lib/index.js#L205 - Emit results to `this.console.log`