Here is my error:
rake aborted! Gem::LoadError: You have already activated rake 10.3.1, but your Gemfile requires rake 10.2.2. Prepending `bundle exec` to yo
You can use rubygems-bundler to solve this. Run the following commands:
rubygems-bundler
$ gem install rubygems-bundler $ gem regenerate_binstubs
$ gem install rubygems-bundler
$ gem regenerate_binstubs
Then try your rake again.