Fix twitter badge, remove gitter

Author: fisker

README.md

@@ -23,11 +23,8 @@
   <a href="#badge">
     <img alt="code style: prettier" src="https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square">
   </a>
-  <a href="https://gitter.im/jlongster/prettier">
-    <img alt="Gitter" src="https://img.shields.io/gitter/room/jlongster/prettier.svg?style=flat-square">
-  </a>
   <a href="https://twitter.com/PrettierCode">
-    <img alt="Follow+Prettier+on+Twitter" src="https://img.shields.io/twitter/follow/prettiercode.svg?label=follow+prettier&style=flat-square">
+    <img alt="Follow+Prettier+on+Twitter" src="https://img.shields.io/badge/%40PrettierCode-9f9f9f?style=flat-square&logo=x&labelColor=555">
   </a>
 </p>