message: Added Codecov badge next to CI badges
  Fixes
diff: <a href="https://circleci.com/gh/facebook/jest"><img src="https://circleci.com/gh/facebook/jest.svg?style=shield" alt="CircleCI Build Status"></a>
  <a href="https://travis-ci.org/facebook/jest"><img src="https://travis-ci.org/facebook/jest.svg?branch=master" alt="Travis Build Status"></a>
  <a href="https://ci.appveyor.com/project/Daniel15/jest/branch/master"><img src="https://ci.appveyor.com/api/projects/status/8n38o44k585hhvhd/branch/master?svg=true" alt="Windows Build Status"></a>
  + <a href="https://codecov.io/gh/facebook/jest"><img src="https://codecov.io/gh/facebook/jest/branch/master/graph/badge.svg" alt="Codecov badge"></a>
  <a href="http://badge.fury.io/js/jest"><img src="https://badge.fury.io/js/jest.svg" alt="npm version"></a>
  <a href="https://dependabot.com/compatibility-score.html?dependency-name=jest&amp;package-manager=npm_and_yarn&amp;version-scheme=semver"><img src="https://api.dependabot.com/badges/compatibility_score?dependency-name=jest&amp;package-manager=npm_and_yarn&amp;version-scheme=semver" alt="SemVer">
  <a href="https://twitter.com/acdlite/status/974390255393505280"><img src="https://img.shields.io/badge/speed-blazing%20%F0%9F%94%A5-brightgreen.svg" alt="Blazing Fast"></a>
  