Add CircleCI and Codecov badges.

Author: rossiam

README.md

@@ -3,6 +3,8 @@
 <p align="center">
 <a href="https://www.npmjs.com/package/@smartthings/smartapp"><img src="https://badgen.net/npm/v/@smartthings/smartapp"/></a>
 <a href="https://www.npmjs.com/package/@smartthings/smartapp"><img src="https://badgen.net/npm/license/@smartthings/smartapp"/></a>
+<a href="https://circleci.com/gh/SmartThingsCommunity/smartapp-sdk-nodejs/tree/master"><img src="https://circleci.com/gh/SmartThingsCommunity/smartapp-sdk-nodejs.svg?style=svg"/></a>
+<a href="https://codecov.io/gh/SmartThingsCommunity/smartapp-sdk-nodejs"><img src="https://codecov.io/gh/SmartThingsCommunity/smartapp-sdk-nodejs/branch/master/graph/badge.svg"/></a>
 <a href="https://status.badgen.net/"><img src="https://badgen.net/xo/status/@smartthings/smartapp"/></a>
 <a href="https://lgtm.com/projects/g/SmartThingsCommunity/smartapp-sdk-nodejs/context:javascript"><img alt="Language grade: JavaScript" src="https://img.shields.io/lgtm/grade/javascript/g/SmartThingsCommunity/smartapp-sdk-nodejs.svg?logo=lgtm&logoWidth=18"/></a>
 <a href="https://lgtm.com/projects/g/SmartThingsCommunity/smartapp-sdk-nodejs/alerts/"><img alt="Total alerts" src="https://img.shields.io/lgtm/alerts/g/SmartThingsCommunity/smartapp-sdk-nodejs.svg?logo=lgtm&logoWidth=18"/></a>