mkdir (remotePath, options = {}) {
    return new Promise((resolve, reject) => {
      const { sftp } = this
      sftp.mkdir(remotePath, options, err => {
        if (err) reject(err)
        else resolve(1)
      })
    })
  }
mkdir

@param {String} remotePath
@param {Object} attributes
An object with the following valid properties:

      mode - integer - Mode/permissions for the resource.
      uid - integer - User ID of the resource.
      gid - integer - Group ID of the resource.
      size - integer - Resource size in bytes.
      atime - integer - UNIX timestamp of the access time of the resource.
      mtime - integer - UNIX timestamp of the modified time of the resource.

      When supplying an ATTRS object to one of the SFTP methods:
      atime and mtime can be either a Date instance or a UNIX timestamp.
      mode can either be an integer or a string containing an octal number.
https://github.com/mscdex/ssh2/blob/master/SFTP.md
@return {Promise}