Preparing for release, 0.8.3.

Author: dblock

CHANGELOG.md

@@ -1,9 +1,8 @@
 ### Changelog
 
-#### 0.8.3 (Next)
+#### 0.8.3 (2019/01/17)
 
 * [#88](https://github.com/slack-ruby/slack-ruby-bot-server/issues/88): Fix: compatibility with Grape 1.2.x - [@dblock](https://github.com/dblock).
-* Your contribution here.
 
 #### 0.8.2 (2018/10/11)