我尝试 heroku run bundle exec rake db:create --trace
并且有错误
rake aborted!
undefined method task' for #<CertApp::Application:0x00000002ad5488>
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:215:i
ninitialize_tasks'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:139:i
n load_tasks'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:77:in
method_missing'
/app/Rakefile:8:in <top (required)>'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/rake_module.rb:25:inlo
ad'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/rake_module.rb:25:in lo
ad_rakefile'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:581:inr
aw_load_rakefile'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:87:in bl
ock in load_rakefile'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:158:ins
tandard_exception_handling'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:86:in lo
ad_rakefile'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:70:inbl
ock in run'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:158:in s
tandard_exception_handling'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/lib/rake/application.rb:68:inru
n'
/app/vendor/bundle/ruby/1.9.1/gems/rake-10.0.2/bin/rake:37:in `'
/app/vendor/bundle/ruby/1.9.1/bin/rake:19:in load'
/app/vendor/bundle/ruby/1.9.1/bin/rake:19:in'
in gemfile
gem 'rake', '0.8.7'
我应该怎么办?