Getting pedant running with rspec 3

@mcquin I was able to get pedant running locally with these changes (although the tests don't all pass yet).  It also sends the output from the pedant subcommands to the current STDOUT.
I was trying to execute `Bundler.with_clean_env` via `shell_out` with `ruby -e`. (Whaaaaaat??) This makes waaaay more sense.