Added capability to validate arrays directly against a schema

The current implementation lacks the ability to validate an array directly against a schema. That is, a schema such as the following always returns as valid: 

```javascript
var s = {
  type: 'array'
}
```

This is not desired when actually wishing to validate the contents of an array (such as a grid), thus shoehorning the user into wrapping their grid in an object. This PR adds a secondary logical path that is available if the schema's type is 'array'. I pulled in all of the tests from https://github.com/flatiron/revalidator/pull/65, since the tests were great, but, sadly, the code was outdated when considered for merging.

Also, performed a tad bit of cleanup in the test file because jshint was driving me mad.