v1.2.0

• Feature: Add any() helper to await first successful fulfillment of operations.
  (#15 by @clue)

  // new: limit concurrency while awaiting first operation to complete successfully
  $promise = Transformer::any($input, 3, function ($data) use ($browser, $url) {
      return $browser->post($url, [], json_encode($data));
  });
  
  $promise->then(function (ResponseInterface $response) {
      echo 'First successful response: ' . $response->getBody() . PHP_EOL;
  });

• Improve test suite to run tests on PHP 7.4 and simplify test matrix
  and add support / sponsorship info.
  (#13 and #14 by @clue)