Update changelog for 2.4.0-beta.3 release

Author: bmac

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 ### Master
 
+### Release 2.4.0-beta.3 (February 26, 2016)
+- [#4125](https://github.com/emberjs/data/pull/4125) [BUGFIX beta] Export more public API's via modules
+- [#4135](https://github.com/emberjs/data/pull/4135) import require
+- [#4137](https://github.com/emberjs/data/pull/4137) [BUGFIX beta] Allow optional spaces when parsing response headers
+- [#4141](https://github.com/emberjs/data/pull/4141) [DOC] Document behavior of object level errors with JSON API
+- [#4147](https://github.com/emberjs/data/pull/4147) Fix key remapping for embedded belongsTo
+- [#4167](https://github.com/emberjs/data/pull/4167) Add blueprints from ember-cli-mocha
+
+
 ### Release 2.4.0-beta.2 (February 2, 2016)
 - [#4082](https://github.com/emberjs/data/pull/4082) Move the date import to where it is used intead of the root module
 - [#4063](https://github.com/emberjs/data/pull/4063) [BUGFIX release] don't load "app" code when loading globals files