message: docs: Do not show coverage badges in README
diff: [![Telegram Group](https://cdn.jsdelivr.net/gh/Patrolavia/telegram-badge@8fe3382b3fd3a1c533ba270e608035a27e430c2e/chat.svg)](https://t.me/nervosnetwork)
  [![Nervos Talk](https://img.shields.io/badge/discuss-on%20Nervos%20Talk-3CC68A.svg)](https://talk.nervos.org/)
  -Branch | Tests | Coverage
  -----------|-------|----------
  -master | [![TravisCI](https://travis-ci.com/nervosnetwork/ckb.svg?branch=master)](https://travis-ci.com/nervosnetwork/ckb) | [![Codecov](https://codecov.io/gh/nervosnetwork/ckb/branch/master/graph/badge.svg)](https://codecov.io/gh/nervosnetwork/ckb/branch/master)
  -develop | [![TravisCI](https://travis-ci.com/nervosnetwork/ckb.svg?branch=develop)](https://travis-ci.com/nervosnetwork/ckb) | [![Codecov](https://codecov.io/gh/nervosnetwork/ckb/branch/develop/graph/badge.svg)](https://codecov.io/gh/nervosnetwork/ckb/branch/develop)
  +master | develop
  +-------|----------
  +[![TravisCI](https://travis-ci.com/nervosnetwork/ckb.svg?branch=master)](https://travis-ci.com/nervosnetwork/ckb) | [![TravisCI](https://travis-ci.com/nervosnetwork/ckb.svg?branch=develop)](https://travis-ci.com/nervosnetwork/ckb)
  ---
  