docs: switched to badges for travis-ci.com

Author: ErikBjare

README.md

@@ -42,8 +42,8 @@
   <a href="https://github.com/ActivityWatch/activitywatch/actions?query=branch%3Amaster">
     <img title="Build Status GitHub" src="https://github.com/ActivityWatch/activitywatch/workflows/Build/badge.svg?branch=master" />
   </a>
-  <a href="https://travis-ci.org/ActivityWatch/activitywatch">
-    <img title="Build Status Travis" src="https://travis-ci.org/ActivityWatch/activitywatch.svg?branch=master" />
+  <a href="https://travis-ci.com/ActivityWatch/activitywatch">
+    <img title="Build Status Travis" src="https://travis-ci.com/ActivityWatch/activitywatch.svg?branch=master" />
   </a>
   <a href="https://ci.appveyor.com/project/ErikBjare/activitywatch">
     <img title="Build Status Appveyor" src="https://ci.appveyor.com/api/projects/status/vm7g9sdfi2vgix6n?svg=true" />