Add v3.9.0-beta.1 to CHANGELOG

[ci skip]

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Ember Changelog
 
+### v3.9.0-beta.1 (February 18, 2019)
+
+- [#17470](https://github.com/emberjs/ember.js/pull/17470) [DEPRECATION] Implements the Computed Property Modifier deprecation RFCs
+  * Deprecates `.property()` (see [emberjs/rfcs#0375](https://github.com/emberjs/rfcs/blob/master/text/0375-deprecate-computed-property-modifier.md)
+  * Deprecates `.volatile()` (see [emberjs/rfcs#0370](https://github.com/emberjs/rfcs/blob/master/text/0370-deprecate-computed-volatile.md)
+  * Deprecates computed overridability (see [emberjs/rfcs#0369](https://github.com/emberjs/rfcs/blob/master/text/0369-deprecate-computed-clobberability.md) 
+- [#17488](https://github.com/emberjs/ember.js/pull/17488) [DEPRECATION] Deprecate this.$() in curly components (see [emberjs/rfcs#0386](https://github.com/emberjs/rfcs/blob/master/text/0386-remove-jquery.md))
+- [#17489](https://github.com/emberjs/ember.js/pull/17489) [DEPRECATION] Deprecate Ember.$() (see [emberjs/rfcs#0386](https://github.com/emberjs/rfcs/blob/master/text/0386-remove-jquery.md))
+- [#17540](https://github.com/emberjs/ember.js/pull/17540) [DEPRECATION] Deprecate aliasMethod
+- [#17487](https://github.com/emberjs/ember.js/pull/17487) [BUGFIX] Fix scenario where aliased properties did not update in production mode
+
 ### v3.8.0 (February 18, 2019)
 
 - [#17143](https://github.com/emberjs/ember.js/pull/17143) / [#17375](https://github.com/emberjs/ember.js/pull/17375) [FEATURE] Implement Element Modifier Manager RFC (see [emberjs/rfcs#0373](https://github.com/emberjs/rfcs/blob/master/text/0373-Element-Modifier-Managers.md)).