performance - localjump and no block given error while starting rails server on c9 -

i'm creating rails 4.2 app , happened while deploying heroku.

i'm using cloud 9,after doing changes listed below tried run rails app , received error:

(master) $ rails s /usr/local/rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.6/lib/bundler/dsl.rb:157:in `group': no block given (yield) (localjumperror)

i replaced gem 'sqlite3 in gemfile with:

group :production    gem 'pg'   gem 'rails_12factor' end  group :development gem 'sqlite3' end 

then changed applicationcontroller file so:

class applicationcontroller < actioncontroller::base # prevent csrf attacks raising exception. # apis, may want use :null_session instead.  protect_from_forgery with: :exception    def hello      render text: "<h1>hello</h1><p>welcome home</p>"    end end 

and changed config.routes.rb file to:

first-app::application.routes.draw    root "application#hello"  

i've searched on place answers came across did not relate editing gemfiles , starting rails server receiving localjumperror + no block given(yield) error.