code: function writeComponentsMap(path, componentsMap) {
    return new Promise((resolve, reject) => {
      const data = JSON.stringify(componentsMap);
      fs.writeFile(path, data, (err) => {
        if (err) {
          return reject(err);
        }
        resolve(data.length);
      });
    });
  }
docs: Writes a component map to the file system.
  
  @param {string} path The path to the file to write to.
  @param {Object} componentsMap The map of components to versions.
  @return {number} The length of data written.