Herokuにアップロードできない

これからアプリケーションを作成しようとしており、最低限ルーティングなどを設定した段階で一度Herokuにアップロードしようとしています。

heroku run rake db:migrateコマンドを打ち込むと以下のようなエラーが出るのですが、これの原因がわかりません。

$ heroku run rake db:migrate
Running rake db:migrate attached to terminal... up, run.2993
rake aborted!
NameError: undefined local variable or method `config' for main:Object
/app/config/environments/production.rb:1:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:274:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:274:in `block in require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:240:in `load_dependency'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:274:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/engine.rb:598:in `block (2 levels) in <class:Engine>'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/engine.rb:597:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/engine.rb:597:in `block in <class:Engine>'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:30:in `instance_exec'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:30:in `run'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:55:in `block in run_initializers'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:44:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:44:in `tsort_each_child'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/initializable.rb:54:in `run_initializers'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/application.rb:352:in `initialize!'
/app/config/environment.rb:5:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/application.rb:328:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/application.rb:328:in `require_environment!'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.0/lib/rails/application.rb:443:in `block in run_tasks_blocks'
Tasks: TOP => db:migrate => environment
(See full trace by running task with --trace)