Build a gem, using jeweler, based on a branch.

gemify_by_branch.rake

desc "Install Gem based on a branch (e.g. rake gemify[master] or rake gemify)."
task :gemify, :branch do |task, args|
  branch    = args[:branch].nil? || args[:branch] == '' ? 'master' : args[:branch]
  
  puts "Going to checkout the #{branch} branch and build the gem for it."
  
  # run commands
  `rm -rf package`
  `git checkout master`
  `git pull origin #{branch}`
  `git checkout #{branch}`
  `rake build`
  `rake install`
  
  # let the user know it is completed
  puts "Completed."
end