Publish 1.6.0?

[jrwats]

package.json has had some dependency issues resolved, for instance, react-scripts isn't a dependency anymore. See also: https://github.com/ruilisi/react-chessground/commit/57f625774fc528d2e185b7a15717ed309907037b

Can we publish v1.6.0 to npm now?

[mehmetsefabalik]

we need this new version, will you be able to help? @hophacker