Cheerio array

Added a utility function to return an array of Cheerio objects. The existing `toArray()` returns an array of DOM elements. `toCheerioArray()` returns an array full of Cheerio objects. 

I didn't add any unit tests because there weren't any for `toArray()`.

## Motivation
I often need to iterate over an array of Cheerio objects and I got tired of writing the `map` function to convert a Cheerio object to an array, so I added it.