function removeDir(relativePath) {
  return new Promise((resolve, reject) => {
    try {
      rimraf(path.join(__dirname, '/../../app/', relativePath), err => {
        if (err) throw err;
      });
      resolve(relativePath);
    } catch (err) {
      reject(err);
    }
  });
}
Remove a directory
@param {string} relativePath
@returns {Promise<any>}