Add rubinius-specific dependencies to get specs running

.travis.yml

@@ -4,7 +4,7 @@ services:
 rvm:
   - 1.9.3
   - jruby-19mode
-  - rbx-2.1.1
+  - rbx
   - 2.0.0
 branches:
   only:
@@ -17,4 +17,4 @@ notifications:
 matrix:
   allow_failures:
     - rvm: jruby-19mode
-    - rvm: rbx-2.1.1
+    - rvm: rbx

Gemfile

@@ -1,2 +1,9 @@
 source 'https://rubygems.org'
 gemspec
+
+platforms :rbx do
+  gem 'rubysl', '~> 2.0'         # if using anything in the ruby standard library
+  gem 'psych'                    # if using yaml
+  gem 'minitest'                 # if using minitest
+  gem 'rubinius-developer_tools' # if using any of coverage, debugger, profiler
+end