Update 'jgem' provider options for newer versions of JRuby

JRuby 1.7.5 upgraded its bundled Rubygems to 2.1.5. As of
Rubygems 2.0, '-y' and '--include-dependencies' have been removed.
Using them will trigger an 'ERROR: invalid option' and cause
installations to fail. Now the 'jgem' provider will filter on the
version of JRuby that's being installed.