version control remote content from 2013-07-notredame 

Modified the version-control-remote lesson to use a purpose-built, "disposable" repository rather than making commits to swcarpentry/boot-camps.git or octocat/Spoon-Knife.git.   Added instructions to create a file, commit it, push it to the user's fork, and submit a pull request, and update the local repositories, and a few notes about how it worked at 2013-06-tufts, 2013-06-chicago, and 2013-07-tufts.