Fix rspec deprecation warnings. .should -> expect().to

[vStone]

Fixes

Using `should` from rspec-expectations' old `:should` syntax without explicitly enabling the syntax is 
deprecated. Use the new `:expect` syntax or explicitly enable `:should` instead. Called from 
/my/vagrant/puppet/modules/upstream/java/spec/unit/facter/java_major_version_spec.rb:14:in `block (4 levels) in <top (required)>'.