support for an array request body

I've added support for the following example:

```console
$ curl http://example.com/config-vars \
  -X PATCH \
  -d '[
         {"name": "FOO", "value": "1"},
         {"name": "BAR", "value": "2"},
       ]'
```
Weird Ruby trick, where you'd use `[*items['example']]`

```ruby
> one = 'item'
> many = ['item', 'item', 'item']
> [*one]
=> ["item"]
> [*many]
=> ["item", "item", "item"]
```