Prepare v1.3.0 release

Author: clue

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 1.3.0 (2018-04-24)
+
+*   Feature: Improve memory consumption by cleaning up unneeded references.
+    (#32 by @clue)
+
 ## 1.2.1 (2017-12-22)
 
 *    README improvements

README.md

@@ -342,7 +342,7 @@ This project follows [SemVer](http://semver.org/).
 This will install the latest supported version:
 
 ```bash
-$ composer require react/promise-timer:^1.2.1
+$ composer require react/promise-timer:^1.3
 ```
 
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.