Update chat badge (#119)

Author: styfle

readme.md

@@ -1,7 +1,7 @@
 # ms
 
 [![Build Status](https://travis-ci.org/zeit/ms.svg?branch=master)](https://travis-ci.org/zeit/ms)
-[![Slack Channel](http://zeit-slackin.now.sh/badge.svg)](https://zeit.chat/)
+[![Join the community on Spectrum](https://withspectrum.github.io/badge/badge.svg)](https://spectrum.chat/zeit)
 
 Use this package to easily convert various time formats to milliseconds.