oops, need older rubygems to work

Rakefile

@@ -30,7 +30,6 @@ end
 namespace :spec do
   desc "Ensure spec dependencies are installed"
   task :deps do
-    sh "gem update --system 2.2.0" # 2.2.1 and 2.2.2 can't install RSpec 3
     {"rdiscount" => "~> 1.6", "ronn" => "~> 0.7.3", "rspec" => "~> 3.0.beta"}.each do |name, version|
       sh "#{Gem.ruby} -S gem list -i '^#{name}$' -v '#{version}' || " \
          "#{Gem.ruby} -S gem install #{name} -v '#{version}' --no-ri --no-rdoc"
@@ -40,14 +39,19 @@ namespace :spec do
   namespace :travis do
     task :deps do
       # Give the travis user a name so that git won't fatally error
-      system("sudo sed -i 's/1000::/1000:Travis:/g' /etc/passwd")
+      system "sudo sed -i 's/1000::/1000:Travis:/g' /etc/passwd"
       # Strip secure_path so that RVM paths transmit through sudo -E
-      system("sudo sed -i '/secure_path/d' /etc/sudoers")
+      system "sudo sed -i '/secure_path/d' /etc/sudoers"
       # Install groff for the ronn gem
-      system("sudo apt-get install groff -y")
-      # Downgrade Rubygems on 1.8 to avoid https://github.com/rubygems/rubygems/issues/784
+      sh "sudo apt-get install groff -y"
       if RUBY_VERSION < '1.9'
-        system("gem update --system 2.1.11")
+        # Downgrade Rubygems on 1.8 so Ronn can be required
+        # https://github.com/rubygems/rubygems/issues/784
+        sh "gem update --system 2.1.14"
+      else
+        # Downgrade Rubygems so RSpec 3 can be instaled
+        # https://github.com/rubygems/rubygems/issues/813
+        sh "gem update --system 2.2.0"
       end
       # Install the other gem deps, etc.
       Rake::Task["spec:deps"].invoke