Update CHANGELOG.md

Author: davideast

CHANGELOG.md

@@ -1,5 +1,5 @@
-<a name="2.0.0-beta.3"></a>
-# [2.0.0-beta.3](https://github.com/angular/angularfire2/compare/2.0.0-beta.2...v2.0.0-beta.3) (2016-08-22)
+<a name="2.0.0-beta.4"></a>
+# [2.0.0-beta.4](https://github.com/angular/angularfire2/compare/2.0.0-beta.2...v2.0.0-beta.3) (2016-08-22)
 
 
 * a handful of package and publish chores (#312) ([ac8c6be](https://github.com/angular/angularfire2/commit/ac8c6be)), closes [#272](https://github.com/angular/angularfire2/issues/272) [#311](https://github.com/angular/angularfire2/issues/311) [#310](https://github.com/angular/angularfire2/issues/310) [#293](https://github.com/angular/angularfire2/issues/293) [#246](https://github.com/angular/angularfire2/issues/246)