Release 1.5.0

Release 1.4.1 (guzzle#137)

Prepare for 1.4.0 (guzzle#123)

* Prepare for 1.4.0

* Added guzzle#128 in the changelog

Tagged v1.3.1

* Adds support for custom task queues.

* Fixed coroutine promise memory leak.

* Update to now catch `\Throwable` on PHP 7+

1.1.0 release

* Update EachPromise to immediately resolve when the underlying promi…

…se iterator

  is empty. Previously, such a promise would throw an exception when its `wait`
  function was called.

* Conditionally require functions.php.

* Updating EachPromise to call next on the underlying promise iterato…

…r as late

  as possible to ensure that generators that generate new requests based on
  callbacks are not iterated until after callbacks are invoked.