readme: add slack hook

closes #98

README.md

diff --git a/README.md b/README.md
index 937f8c1..32f6dee 100644
--- a/README.md
+++ b/README.md
@@ -238,6 +238,9 @@
 * [`github.com/sebest/logrusly`](https://github.com/sebest/logrusly)
   Send logs to Loggly (https://www.loggly.com/)
 
+* [`github.com/johntdyer/slackrus`](https://github.com/johntdyer/slackrus)
+  Hook for Slack chat.
+
 #### Level logging
 
 Logrus has six logging levels: Debug, Info, Warning, Error, Fatal and Panic.