Update build to use `npm ci` to improve reliability

[natemcmaster]

https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable

This is not yet available in Node 8.x (see nodejs/node#21593).

[natemcmaster]

We have had continual problems with the reliability of npm install in VSTS builds. It would be nice to switch to something that is designed for CI environments.

[analogrelay]

We could install the latest npm as part of the build script, there's no need to be tied to the version that comes with Node.

[natemcmaster]

That would work too.

Also, we've talked about using yarn instead. My experience with Yarn so far has been that it's fast and reliable and doesn't require a special ci mode.

[analogrelay]

Looks like npm ci is significantly faster than yarn according to the post you linked. I'm not too worried either way, but I do want the install of whatever tools we use to be simple and as automated as possible.

[BrennanConroy]

Blocked #2823 (comment)

[analogrelay]

Blocked on moving everything to AzDO