[now-client] Fix publish output

[styfle]

Fixes #3310

The root package.json file is copied to dist by tsc because of a relative import. This causes npm files property to be nested and therefore skip publishing most of the files.

import pkg from '../../package.json';

Disabling resolveJsonModule and using require() instead fixed it.

However, this change caused now-cli build to fail so I had to change the way now-client gets imported.