Travis - Ruby 2.1.0, Rubinius, JRuby

1. Added Ruby 2.1.0, Rubinius, JRuby to Travis config.
2. Updated deprecated syntax in specs to match the other specs.
3. Added Rubinius gems to Gemfile.

JRuby and Rubinius have allowed failures because they don't support the embedded shell behavior that is available on MRI VMs.