How can I create a bill with the BitPay PHP client library?

Here's the exact request data you can use to create your bill and the successful response data returned from our gateway:

[request] => {"items":[{"description":"somecooldescription","price":1.45,"quantity":5}],"guid":"6eae4e0e-e8cf-386e-f767-79c43de60806","nonce":1422407765.2744,"token":"7U24AhTLM3A36iN4bUsEvcEcxB8UeEPSn7ghEYuCbkoc"}
[response] => {"facade":"merchant/bill","data":{"id":"AZwvMKsLuYyxisfVJqLUsD","status":"draft","items":[{"price":1.45,"quantity":5,"description":"somecooldescription"}],"createdDate":"2015-01-28T01:13:00.088Z","currency":"BTC","token":"6Qo7YAcW1b4LBXmSo9UB6izPHs3BHZSCBt8fNhvo2DQEGTZajySqBafWuSxBLCti9w"}}

Here's the slightly modified Client::createBill() function used for this example:

public function createBill(\Bitpay\Bill $bill)
{
 $request = $this->createNewRequest();
 $request->setMethod(Request::METHOD_POST);
 $request->setPath('bills');
 $body = array(
 'items' => array(array('description' => 'somecooldescription', 'price' => 1.45, 'quantity' => 5)),
 'guid' => Util::guid(),
 'nonce' => Util::nonce(),
 'token' => '7U24AhTLM3A36iN4bUsEvcEcxB8UeEPSn7ghEYuCbkoc',
 );
 $request->setBody(json_encode($body));
 $this->addIdentityHeader($request);
 $this->addSignatureHeader($request);
 $this->request = $request;
 $this->response = $this->sendRequest($request);
 $response = json_decode($this->response->getBody(), true);
 return array('request' => json_encode($body), 'response' => $this->response->getBody());
}

And here's the contents of my billtest.php script used for this exercise:

 array(
 'network' => 'testnet',
 'public_key' => '/tmp/public.key',
 'private_key' => '/tmp/private.key',
 'key_storage' => 'Bitpay\Storage\FilesystemStorage',
 )
 )
 );
$client = $bitpay->get('client');
$tokens = $client->getTokens();
$client->setAdapter(new \Bitpay\Client\Adapter\CurlAdapter());
$bill = new \Bitpay\Bill;
$info = $client->createBill($bill);
print_r($info);