title: Standard.js in Travis CI "Configuration for rule "comma-dangle" is invalid"
body: <p>I just added <code>npm run standard</code> to Travis CI. I'm getting this error.</p>
  
  <pre><code>&gt; standard
  standard: Unexpected linter output:
  Error: standard:
      Configuration for rule "comma-dangle" is invalid:
      Value "[object Object]" must be an enum value.
  Referenced from: /home/travis/build/project/node_modules/standard/eslintrc.json
      at validateRuleOptions (/home/travis/build/project/node_modules/eslint/lib/config/config-validator.js:116:15)
      at /home/travis/build/project/node_modules/eslint/lib/config/config-validator.js:163:13
      at Array.forEach (native)
      at Object.validate (/home/travis/build/project/node_modules/eslint/lib/config/config-validator.js:162:35)
      at load (/home/travis/build/project/node_modules/eslint/lib/config/config-file.js:518:19)
      at /home/travis/build/project/node_modules/eslint/lib/config/config-file.js:386:36
      at Array.reduceRight (native)
      at applyExtends (/home/travis/build/project/node_modules/eslint/lib/config/config-file.js:363:28)
      at Object.load (/home/travis/build/project/node_modules/eslint/lib/config/config-file.js:525:22)
      at loadConfig (/home/travis/build/project/node_modules/eslint/lib/config.js:64:33)
  If you think this is a bug in `standard`, open an issue: https://github.com/feross/standard/issues
  </code></pre>
  
  <p>In the project itself it doesn't contain much with this file.</p>
  
  <p><a href="https://github.com/feross/standard/blob/master/eslintrc.json" rel="nofollow noreferrer">https://github.com/feross/standard/blob/master/eslintrc.json</a></p>