async checkNewVersion() {
    const response = await axios({
      method: 'get',
      url: this.manifest.manifestUrl,
      responseType: 'json'
    });

    return semver.gt(response.data.version, this.manifest.version);
  }
Check the latest available version of the application by requesting the manifest specified in `manifestUrl`.

@async
@method
@returns {Promise.<boolean>}