docs: function promiseCommand(command) {
      const opts = {
          env: process.env
      };
      console.log('>>>>', command)
      return spawnShell(command, opts).exitPromise
          .then((exitCode) => {
              if (exitCode === 0) {
                  return;
              } else {
                  throw Error("Exit " + exitCode)
              }
          })
  }