Properly fix Rubinius dependencies in Gemfile & Travis integration.

Before Rubinius 2.2.0, some parts of the stdlib were lazily loaded, even
if not included in the Gemfile. Now it's 100% required to include the
gem 'rubysl', otherwise the stdlib is not available entirely, breaking
everything.

Also, the rubysl-test-unit gem was depending on minitest ~> 4.7, thus causing
conflicts with Rails's dependency on minitest 5. That is not the case
anymore since rubysl-test-unit 2.0.2, so it is completely safe to
include it fully.

When Travis is going to update RVM to 1.24, it'll be safe to use rbx-2,
thus picking new versions automatically.

2 files changed, 3 insertions, 5 deletions

diff --git a/.travis.yml b/.travis.yml
index b97bd8fd32..cb6a5f1128 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ before_install:
 rvm:
   - 1.9.3
   - 2.0.0
-  - rbx-2.1.1
+  - rbx-2.2.1
   - jruby-19mode
 env:
   - "GEM=railties"
diff --git a/Gemfile b/Gemfile
index e82b4c2b27..1422da2723 100644
--- a/Gemfile
+++ b/Gemfile
@@ -79,10 +79,8 @@ platforms :jruby do
 end
 
 platforms :rbx do
-  gem 'psych'
-  gem 'rubysl-mathn'
-  gem 'rubysl-matrix'
-  gem 'rubysl-rexml'
+  gem 'psych', '~> 2.0'
+  gem 'rubysl', '~> 2.0'
 end
 
 # gems that are necessary for ActiveRecord tests with Oracle database