[1] Chrominator looks interesting. jesg/gowan is the maintainer for PhantomJS GhostDriver, so the API looks extensive. Another project that I heard recently is Navalia [4], which uses GraphQL type of queries to run headless Chrome. Also worth noting is Chromy [5] by a Japanese developer; it's one of the earliest to market (released in early May). BackstopJS maintainer also looks to be in active development using Chromy.
[4] https://github.com/joelgriffith/navalia
[5] https://github.com/OnetapInc/chromy