Add 2.7.3 to the CHANGELOG.md.

[ci skip]

CHANGELOG.md

@@ -44,6 +44,15 @@
 - [#13855](https://github.com/emberjs/ember.js/pull/13855) [FEATURE ember-runtime-enumerable-includes] Enable by default.
 - [#13855](https://github.com/emberjs/ember.js/pull/13855) [FEATURE ember-testing-check-waiters] Enable by default.
 
+### 2.7.3 (September 6, 2016)
+
+- [#14219](https://github.com/emberjs/ember.js/pull/14219) [BUGFIX] Fix issue with mutating template's metadata.
+
+### 2.7.2 (August 30, 2016)
+
+- [#13895](https://github.com/emberjs/ember.js/pull/13895) [BUGFIX] Fix template meta lookup with tagless and blockless components.
+- [#14075](https://github.com/emberjs/ember.js/pull/14075) [BUGFIX] In which we revert route-recognizer to the version used in Ember 2.6. 😢
+
 ### 2.7.1 (August 15, 2016)
 
 - [#13920](https://github.com/emberjs/ember.js/pull/13920) [BUGFIX] Add more info to the `Ember.Binding` deprecation.