execNodist = function execNodist(args, cb){
  var stdout = '';
  var stderr = '';
  var nodistCmd = path.resolve(__dirname + '/../bin/nodist.cmd');
  debug('execNodist','executing',nodistCmd,args.join(' '));
  var cp = spawn(
    nodistCmd,
    args,
    {
      env: {
        NODIST_PREFIX: testPath,
        NODIST_NODE_MIRROR: n.sourceUrl,
        NODIST_IOJS_MIRROR: n.iojsSourceUrl,
        HTTP_PROXY: proxy,
        DEBUG: process.env.DEBUG
      }
    }
  );
  if(process.env.TEST){
    cp.stdout.pipe(process.stdout);
    cp.stderr.pipe(process.stderr);
  }
  cp.stdout.on('data',function(chunk){
    stdout = stdout + chunk.toString();
  });
  cp.stderr.on('data',function(chunk){
    stderr = stderr + chunk.toString();
  });
  cp.on('error', function(err){
    debug('execNodist', 'exec failed with error', err);
    cb(err);
  });
  cp.on('close', function(code){
    var err = null;
    debug('execNodist', 'exec completed with', { err, stdout, stderr, code });
    cb(err, stdout, stderr, code);
  });
}
Exec Nodist for Testing
@param {Array} args
@param {function} cb