This also moves other modules and packages into `embark-core` which are
affected by the move of `Engine`.
It did some clean-up of some modules (e.g. `lib/utils/utils.js` had a lot of
stuff that was not used anywhere).
This is the first step to start typing our core inside out. For now we're just
moving code into their dedicated package, after that we can address making
use of TypeScript features as we see fit.
BREAKING CHANGE:
node: >=10.17.0 <12.0.0
npm: >=6.11.3
yarn: >=1.19.1
node v10.17.0 is the latest in the 10.x series and is still in the Active LTS
lifecycle. Embark is still not compatible with node's 12.x and 13.x
series (because of some dependencies), otherwise it would probably make sense
to bump our minimum supported node version all the way to the most recent 12.x
release.
npm v6.11.3 is the version that's bundled with node v10.17.0.
yarn v1.19.1 is the most recent version as of the time node v10.17.0 was
released.