undefined method `rails_metrics'

After installing rails_metrics on my app, when I run "rails g rails_metrics Metric" this is what I get:

DEPRECATION WARNING: railtie_name is deprecated and has no effect. (called from  at /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics/engine.rb:3)

/*****/.rvm/gems/ruby-1.9.2-head/gems/railties-3.0.0.beta2/lib/rails/railtie/configuration.rb:59:in `method_missing': undefined method `rails_metrics' for # (NoMethodError)

    from /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics/engine.rb:6:in `'

    from /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics/engine.rb:2:in `'

    from /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics/engine.rb:1:in `'

    from /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics.rb:112:in `require'

    from /*****/.rvm/gems/ruby-1.9.2-head/bundler/gems/rails_metrics-9fc009a4f0aaaf533f1dd284dd9961b905e5b8db-master/lib/rails_metrics.rb:112:in `'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:45:in `require'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:45:in `block (2 levels) in require'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:40:in `each'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:40:in `block in require'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:39:in `each'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler/runtime.rb:39:in `require'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/bundler-0.9.16/lib/bundler.rb:73:in `require'

    from /*****/Workspace/CODENAMED/nancyapp/config/application.rb:7:in `'

    from /*****/Workspace/CODENAMED/nancyapp/config/environment.rb:2:in `require'

    from /*****/Workspace/CODENAMED/nancyapp/config/environment.rb:2:in `'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/railties-3.0.0.beta2/lib/rails/commands.rb:29:in `require'

    from /*****/.rvm/gems/ruby-1.9.2-head/gems/railties-3.0.0.beta2/lib/rails/commands.rb:29:in `'

    from script/rails:9:in `require'

    from script/rails:9:in `'

Running it on 3.0.0.beta2 and Ruby 1.9.2-head, via RVM btw… :)

Cheers,
~Levi Figueira