Scala has a built in function that checks the java version is correct, e.g.

scala.util.Properties.isJavaAtLeast("1.7")

We should use this built-in rather than reimplement this functionality in CheckJavaVersion. It would make our code simpler and more understandable. Note that there is also currently a bug in that the error message. It always requires 1.7, even if we ever changed it to require a later version.