old_contents: var editor = require('../');
  editor('beep.json', function (code, sig) {
      console.log('finished editing with code ' + code);
  });
  
new_contents: var editor = require('../');
  editor(__dirname + '/beep.json', function (code, sig) {
      console.log('finished editing with code ' + code);
  });
  
subject: use __dirname