remove README badges for codecov/appveyor

Author: fivetanley

README.md

@@ -5,8 +5,6 @@
 
 [![Version](https://img.shields.io/npm/v/@heroku-cli/typescript-api-schema.svg)](https://npmjs.org/package/@heroku-cli/typescript-api-schema)
 [![CircleCI](https://circleci.com/gh/heroku/typescript-api-schema/tree/master.svg?style=shield)](https://circleci.com/gh/heroku/typescript-api-schema/tree/master)
-[![Appveyor CI](https://ci.appveyor.com/api/projects/status/github/heroku/typescript-api-schema?branch=master&svg=true)](https://ci.appveyor.com/project/heroku/typescript-api-schema/branch/master)
-[![Codecov](https://codecov.io/gh/heroku/typescript-api-schema/branch/master/graph/badge.svg)](https://codecov.io/gh/heroku/typescript-api-schema)
 [![Downloads/week](https://img.shields.io/npm/dw/@heroku-cli/typescript-api-schema.svg)](https://npmjs.org/package/@heroku-cli/typescript-api-schema)
 [![License](https://img.shields.io/npm/l/@heroku-cli/typescript-api-schema.svg)](https://github.com/heroku/typescript-api-schema/blob/master/package.json)