Switch to NPM

[Mike Simmonds]

Package (if applicable)
All

The task
Switch to NPM:

• Ensure Travis, Lerna and package.json scripts are updated.
• Use npm ci where applicable.
• Remove Yarn workspaces
• Update README
• Switch yarn.lock > package-lock.json

Additional context
NPM CI appears to be faster that other options available.
When this repo was started Yarn offered a lot more than NPM, now NPM is catching up we should explore.

[Mike Simmonds]

I think this is going to need a deeper look especially around the removal of Yarn workspaces.

[arash kiani]

@simmo just wondering why you want to swap yarn with npm ?

[Mike Simmonds]

• @sburrows-zone gave me a nudge that npm ci seems to be benchmarking faster - https://blog.npmjs.org/post/171556855892/introducing-npm-ci-for-faster-more-reliable
• NPM does security audits by default