Adding esq as an alternative to elastic.js

[esq](https://github.com/holidayextras/esq) allows you to build queries easily. It handles building the object based on the arguments you pass into the function. For example, calling `esq.query('bool', ['must'], { match: { user: 'foobar' } })` will produce:

```
{
  bool: {
    must: [
      {
        match: { 
          user: 'foobar'
        }
      }
    ]
  }
}
```