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"},
       ]'
```
i pushed this changed. the initial `data = nil` needs to stick around due to scoping