Changed to use scala 2.12.0 in README.
Changed to use scala 2.12.0 in README.

scalatest/scalatest,scalatest/scalatest,cheeseng/scalatest,cheeseng/scalatest,dotty-staging/scalatest,dotty-staging/scalatest,scalatest/scalatest,cheeseng/scalatest,dotty-staging/scalatest