Remove old gemspec
Remove old gemspec

This is not supported by bundler.

fphilipe/premailer-rails,controlshift/premailer-rails,doorkeeper/premailer-rails,uswitch/premailer-rails,controlshift/premailer-rails,fphilipe/premailer-rails,doorkeeper/premailer-rails,controlshift/premailer-rails,uswitch/premailer-rails,fphilipe/premailer-rails