[CHANGELOG] Imported missing versions from support [ci skip]

Imported versions `0.8.2` and `0.8.3` from
support/0.8 branch.

Author: vimishor

CHANGELOG.md

@@ -19,6 +19,16 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   - Removed deprecated methods from `Api` (_childFactory, processResponse, authorize_)
   - Removed transport object dependency from `Api`.
 
+## 0.8.3 / 2017-05-15
+
+### Fixed:
+  - Client::setApiVersion should accept only argument of type string (issue #57)
+
+## 0.8.2 / 2017-01-10
+
+### Fixed:
+  - Added missing polyfill for "json_last_error_msg".
+
 ## 0.8.1 / 2016-05-08
 
 ### Fixed: