Solve cocoapods, ruby, gems, brew conflicts...

gistfile1.txt

Open Terminal and enter:

gem uninstall cocoapods  (Select 'All versions' option.)
sudo rvm implode  (Confirm with 'yes' when prompted.)
sudo brew doctor
sudo brew update
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
\curl -L https://get.rvm.io | bash -s stable --ruby
rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup (Maybe not needed)
sudo gem update --system
gem install cocoapods

Source: http://railsapps.github.io/installrubyonrails-mac.html