Function cmdAsync

test/cmd.js:234–240

(...commandArgs)

//

function cmdAsync(...commandArgs) {
  return new Promise((resolve) => {
    shell.cmd(...commandArgs, (code, stdout, stderr) => {
      resolve({ code, stdout, stderr });
    });
  });
}

// TODO(nfischer): enable after we implement async.
test.skip('no callback', t => {