[#1871] Updated the regular expression to not require "java" prefix and
include letters and a dash to support Heroku Java 8 version string
'openjdk version "1.8.0_20-slim"'. Also prints out the version string if
the specific version cannot be determined to enable debugging.
Merge pull request #816 from tazmaniax/lighthouse-1871-patch

[#1871] Play java version detection does not work on heroku