Support js-yaml options

* I updated all the test to work fine.
* I updated the main script to support [js-yaml options](https://github.com/nodeca/js-yaml#safeload-string---options-).
* I updated all the dependencies.
* I removed unnecessary bower.json.
* I updated .jshintrc.
  * Now JSHint supports `mocha` option so we don't have to pre-define global variables of Mocha explicitly. 

Before merging this PR, please enable [Travis CI build](https://travis-ci.org/jonschlinkert/read-yaml/builds).
I'll show you an example using [read-yaml-promise](https://github.com/shinnn/read-yaml-promise) which I created a little while ago.

1. [The target file is encoded in UCS-2](https://github.com/shinnn/read-yaml-promise/blob/master/test/fixture-ucs2.yaml). (We can read the content on browser but don't care about it. Github seems to encode non-utf-8 files to utf-8 as possible for browsing.)
2. [Read the file with UCS-2 encoding](https://github.com/shinnn/read-yaml-promise/blob/master/test/test.js#L14-L16). The function get an utf-8-encoded YAML string.
3. Inside the function, js-yaml parses the utf-8-encoded string.