Preparing for release, 0.12.1.

Author: dblock

CHANGELOG.md

@@ -1,9 +1,8 @@
 ### Changelog
 
-#### 0.12.1 (Next)
+#### 0.12.1 (2020/5/16)
 
 * [#118](https://github.com/slack-ruby/slack-ruby-bot-server/pull/118): Do not fail to start on errors in `Team#purge!` - [@dblock](https://github.com/dblock).
-* Your contribution here.
 
 #### 0.12.0 (2020/4/26)