chore: remove travis-ci badge (#12430)

README.md

@@ -16,7 +16,6 @@
   <a href="https://www.npmjs.com/package/babel-core"><img alt="v6 npm Downloads" src="https://img.shields.io/npm/dm/babel-core.svg?maxAge=43200&label=v6%20downloads"></a>
 </p>
 <p align="center">
-  <a href="https://travis-ci.com/babel/babel"><img alt="Travis Status" src="https://img.shields.io/travis/com/babel/babel/main.svg?label=travis&maxAge=43200"></a>
   <a href="https://circleci.com/gh/babel/babel"><img alt="CircleCI Status" src="https://img.shields.io/circleci/project/github/babel/babel/main.svg?label=circle&maxAge=43200"></a>
   <a href="https://codecov.io/github/babel/babel"><img alt="Coverage Status" src="https://img.shields.io/codecov/c/github/babel/babel/main.svg?maxAge=43200"></a>
   <a href="https://slack.babeljs.io/"><img alt="Slack Status" src="https://slack.babeljs.io/badge.svg"></a>