Smarterer, a Boston-based Google Ventures-backed startup that offers skills test software for companies, said Wednesday it has been acquired by a Utah-based online tech company Pluralsight for $75 million. Smarterer, founded in 2010, had raised about $4.6 million from investors such as Google Ventures, New York-based venture firm Rethink Education, Silicon Valley-based True Ventures and Boston Seed Capital. Smarterer, which has about 10 employees, offers an enterprise skills assessment software…