Move some root devDependencies to appropriate packages

[fahad19]

Since we use Lerna for managing our monorepo, we benefit by keeping majority of our common devDependencies in the root package.json.

Packages like Babel, ESLint, etc are all listed as devDependencies. Also also all site related packages (like metalsmith) are listed in root package.json too.

But there are also some, which are not common across all packages:

• http-server (examples only)
• jsdom (only frint-test-utils need it, iirc)
• live-server (examples only)
• react (only frint-react and frint-react-server should need it)
• react-addons-test-utils (only frint-react and frint-react-server should need it)
• react-dom (only frint-react and frint-react-server should need it)
• rxjs

They should either be moved to appropriate packages as their own devDependencies, or removed altogether (because examples have their own package.json files now).