add failing test for RequireJS coverage on node. see #23
add hook.hookRunInThisContext and automatically call it on run-with-cover for RequireJS support. see #23
Merge pull request #26 from millermedeiros/master

add vm.runInThisContext hook and automatically call it on run-with-cover for RequireJS support.

Going to merge this as-is and then commit a change to only call this hook if a command line option is passed in.