Rails::Info doesn't require version for unwanted frameworks

[#3124 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

railties/builtin/rails_info/rails/info.rb

@@ -29,9 +29,11 @@ def frameworks
       end
 
       def framework_version(framework)
+        if Object.const_defined?(framework.classify)
           require "#{framework}/version"
           "#{framework.classify}::VERSION::STRING".constantize
         end
+      end
 
       def edge_rails_revision(info = git_info)
         info[/commit ([a-z0-9-]+)/, 1] || freeze_edge_version