Update to commit 5174cb4 from git@github.com:gedex/wp-slack.git

Includes the following commit(s):

commit 5174cb4d766b9c0038a5003e5f4a0b268d9ddbba
Author: Akeda Bagus <akeda@x-team.com>

    Removes unrelated content in readme.

M	readme.md
M	readme.txt


git-svn-id: https://plugins.svn.wordpress.org/slack/trunk@892187 b8457f37-d9ea-0310-8a92-e5e31aec5664