Updated date of 0.8.9 release

Author: kmvanbrunt

CHANGELOG.md

@@ -15,7 +15,7 @@
        * ``cmd2.Cmd.postparsing_postcmd()`` - equivilent functionality available
          via ``cmd2.Cmd.register_postcmd_hook()``
 
-## 0.8.9 (TBD 2018)
+## 0.8.9 (August TBD, 2018)
 * Bug Fixes
     * Fixed extra slash that could print when tab completing users on Windows