No way to batch requests

[shadowhand]

It would be good to expose the batch endpoint. Ideally something like this:

$create_users = [
    'rid1' => ['first_name' => 'John', 'last_name' => 'Doe'],
    ...
];
$responses = $wheniwork->batch('post', 'users', $create_users);

When the $responses come back, I would like to have it indexed by the keys of requests, rather than assuming FIFO ordering.