Convert all open github tickets to a PivotalTracker project's Icebox as new strories

   1. Change the constants below accordingly for your project.
   2. Change the options in list_repo() method for your GitHub project.
   3. Change the options in stories.create() method accordingly.
   4. Change the options in notes.create() method accordingly.
   5. gem install github_api
   6. gem install pivotal-tracker
   7. Save this code to a .rb file (github_to_pivotaltr.rb), and chmod it executable [775].
   8. Run this file: ./github_to_pivotaltr.rb