Add the rails_12factor heroku gem to support deploys on rails4.:
Add rails_12factor gem when deploying to heroku in curriculum
Adds CPU type checking for OSX during version check.
Added an updated image to show processor type.
Corrections from railsbridge 20130727
  Wrong directory to rm -rf specified for linux clean up
  Rails 4 is valid too
  rails installer can install ruby on osx
added notes for rails 3.x users about routes and getting the root route starting
At this point in the curriculum the votes routes do not exist - remove.
Merge branch 'tmg/minor_corrections_201307' of https://github.com/tgaff/docs into tgaff-tmg/minor_corrections_201307
Merge branch 'rails3_notes_for_curriculum' of https://github.com/rcode5/docs into rcode5-rails3_notes_for_curriculum
Merge branch 'tmg/minor_corrections_201307_rake_routes' of https://github.com/tgaff/docs into tgaff-tmg/minor_corrections_201307_rake_routes
Updated route console output to look like Rails 4 version

Added references to in-browser routes page (/rails/info)
Changed test runner instructions to run under 'bundle exec' to match CI. The tests were failing under the prior instructions.
Incorporated suggestion to use 'rake spec' but run it in context of the bundled gems.
Merge pull request #223 from tdenkinger/update_readme_for_test_runner

Changed test runner instructions to run under 'bundle exec' to match CI....
Merged master into branch.