CHANGES.md in twilio-ruby-5.12.4 vs CHANGES.md in twilio-ruby-5.13.0

@@ -1,7 +1,20 @@
 twilio-ruby changelog
 =====================
 
+[2018-09-20] Version 5.13.0
+----------------------------
+**Preview**
+- Add `Form` resource to Authy preview given a `form_type`
+- Add Authy initial api-definitions in the 4 main resources: Services, Entities, Factors, Challenges
+
+**Pricing**
+- add voice_numbers resource (v2)
+
+**Verify**
+- Move from preview to beta **(breaking change)**
+
+
 [2018-08-31] Version 5.12.4
 ----------------------------
 **Library**
 - PR #427: VCORE-3651 Add support for *for* attribute in twiml element. Thanks to @nmahure!