Prebid Core: update npm install to ci & remov (#7369)

README.md

@@ -1,6 +1,5 @@
 [![Build Status](https://circleci.com/gh/prebid/Prebid.js.svg?style=svg)](https://circleci.com/gh/prebid/Prebid.js)
 [![Percentage of issues still open](http://isitmaintained.com/badge/open/prebid/Prebid.js.svg)](http://isitmaintained.com/project/prebid/Prebid.js "Percentage of issues still open")
-[![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/prebid/Prebid.js.svg)](http://isitmaintained.com/project/prebid/Prebid.js "Average time to resolve an issue")
 [![Code Climate](https://codeclimate.com/github/prebid/Prebid.js/badges/gpa.svg)](https://codeclimate.com/github/prebid/Prebid.js)
 [![Coverage Status](https://coveralls.io/repos/github/prebid/Prebid.js/badge.svg)](https://coveralls.io/github/prebid/Prebid.js)
 [![devDependencies Status](https://david-dm.org/prebid/Prebid.js/dev-status.svg)](https://david-dm.org/prebid/Prebid.js?type=dev)
@@ -152,7 +151,7 @@ Building with just these adapters will result in a smaller bundle which should a
 
 **Build standalone prebid.js**
 
-- Clone the repo, run `npm install`
+- Clone the repo, run `npm ci`
 - Then run the build:
 
         $ gulp build --modules=openxBidAdapter,rubiconBidAdapter,sovrnBidAdapter