Update deps and dotfiles

* I updated [gulp-util](https://github.com/gulpjs/gulp-util) and [should.js](https://github.com/shouldjs/should.js).
  * Currently should.js doesn't have `.contain()` method but [`.containEql`](https://github.com/shouldjs/should.js#containeqlothervalue) method.
  * According to [the document](https://github.com/shouldjs/should.js#lengthnumber-and-lengthofnumber):
    
    > `.length` and `.lengthOf` change the chain's object to the given length value, so be careful when chaining!
* I updated .jshintrc. From v2.5.0, [JSHint doesn't support `trailing`, `smarttabs` and `white` options](https://github.com/jshint/jshint/releases/tag/2.5.0).
* I fixed .travis.yml.
  * I removed node `0.9` because [Travis CI doesn't support Node v0.9](http://docs.travis-ci.com/user/languages/javascript-with-nodejs/#Choosing-Node-versions-to-test-against).