Rubinius support

[marcelotto]

Travis on rbx-2 failed with:

A syntax error has occurred:
    expecting keyword_end: /home/travis/build/marcelotto/sycamore/lib/sycamore/tree.rb:323:18
Code:
      tree.each do |node, child|
                 ^
Backtrace:
    CodeTools::Melbourne#syntax_error at /home/travis/.rvm/rubies/rbx-2/runtime
                                         /gems/rubinius-melbourne-2.3.1.0/lib
                                         /rubinius/melbourne.rbc:48
      CodeTools::Melbourne#parse_file at /home/travis/.rvm/rubies/rbx-2/runtime
                                         /gems/rubinius-melbourne-2.3.1.0/lib
                                         /rubinius/melbourne.rbc:61
 CodeTools::Compiler::FileParser#parse at /home/travis/.rvm/rubies/rbx-2/runtime
                                          /gems/rubinius-compiler-2.3.1/lib
                                          /rubinius/compiler/stages.rbc:225
  CodeTools::Compiler::Parser(CodeTools::Compiler::FileParser)#run at \
          /home/travis/.rvm/rubies/rbx-2/runtime/gems/rubinius-compiler-2.3.1/lib/rubinius/compiler/stages.rbc:207
              CodeTools::Compiler#run at /home/travis/.rvm/rubies/rbx-2/runtime
                                         /gems/rubinius-compiler-2.3.1/lib
                                         /rubinius/compiler/compiler.rbc:359
          CodeTools::Compiler.compile at /home/travis/.rvm/rubies/rbx-2/runtime
                                         /gems/rubinius-compiler-2.3.1/lib
                                         /rubinius/compiler/compiler.rbc:89
     Rubinius::CodeLoader#compile_file at kernel/delta/code_loader.rb:217
        Rubinius::CodeLoader#load_file at kernel/delta/code_loader.rb:190
          Rubinius::CodeLoader#require at kernel/common/code_loader.rb:128
          Rubinius::CodeLoader.require at kernel/common/code_loader.rb:241
                Kernel(Object)#require at kernel/common/kernel.rb:756
                     Object#__script__ at lib/sycamore.rb:5
          Rubinius::CodeLoader.require at kernel/common/code_loader.rb:247
                Kernel(Object)#require at kernel/common/kernel.rb:756
                     Object#__script__ at spec/spec_helper.rb:2
          Rubinius::CodeLoader.require at kernel/common/code_loader.rb:247
  Kernel(RSpec::Core::Configuration)#require at kernel/common/kernel.rb:756
 { } in RSpec::Core::Configuration#requires= at vendor/bundle/rbx/2.1/gems
                                                /rspec-core-3.4.4/lib/rspec/core
                                                /configuration.rb:1295
                            Array#each at kernel/bootstrap/array.rb:76
 RSpec::Core::Configuration#requires= at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/lib/rspec/core
                                         /configuration.rb:1295
  { } in RSpec::Core::ConfigurationOptions#process_options_into at \
          vendor/bundle/rbx/2.1/gems/rspec-core-3.4.4/lib/rspec/core/configuration_options.rb:109
                            Array#each at kernel/bootstrap/array.rb:76
 RSpec::Core::ConfigurationOptions#process_options_into at vendor/bundle/rbx/2.1
                                                           /gems
                                                           /rspec-core-3.4.4/lib
                                                           /rspec/core
                                                           /configuration_options.rb:108
 RSpec::Core::ConfigurationOptions#configure at vendor/bundle/rbx/2.1/gems
                                                /rspec-core-3.4.4/lib/rspec/core
                                                /configuration_options.rb:21
            RSpec::Core::Runner#setup at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/lib/rspec/core
                                         /runner.rb:105
              RSpec::Core::Runner#run at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/lib/rspec/core
                                         /runner.rb:92
              RSpec::Core::Runner.run at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/lib/rspec/core
                                         /runner.rb:78
           RSpec::Core::Runner.invoke at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/lib/rspec/core
                                         /runner.rb:45
                    Object#__script__ at vendor/bundle/rbx/2.1/gems
                                         /rspec-core-3.4.4/exe/rspec:4
      Rubinius::CodeLoader#load_script at kernel/delta/code_loader.rb:66
      Rubinius::CodeLoader.load_script at kernel/delta/code_loader.rb:152
               Rubinius::Loader#script at kernel/loader.rb:656
                 Rubinius::Loader#main at kernel/loader.rb:842
/home/travis/.rvm/rubies/rbx-2/bin/rbx -I/home/travis/build/marcelotto/sycamore/vendor/bundle/rbx/2.1/gems/rspec-core-3.4.4/lib:/home/travis/build/marcelotto/sycamore/vendor/bundle/rbx/2.1/gems/rspec-support-3.4.1/lib /home/travis/build/marcelotto/sycamore/vendor/bundle/rbx/2.1/gems/rspec-core-3.4.4/exe/rspec --pattern spec/\*\*\{,/\*/\*\*\}/\*_spec.rb failed

[marcelotto]

Cause: rubinius/rubinius-code#7