code: function createPagesMetadata(src, dest) {
    return new Promise((resolve, reject) => {
      const thisTaskName = swlog.logSubStart('create metadata file');
      const outputStr = sketchtoolExec(`metadata ${src}`)
      const ignoredPages = ['Symbols', 'Icon Sheet', '------------']
  
      let customObj = { categories: [] };
      const dataObj = JSON.parse(outputStr);
  
      // Loop through pages, then arboards, to create a
      // simple mapping of names (ignoring certain pages)
      // and naming pages "categories" and artboards "icons"
      for (const pageId in dataObj.pagesAndArtboards) {
        if (dataObj.pagesAndArtboards.hasOwnProperty(pageId)
          && ! ignoredPages.includes(dataObj.pagesAndArtboards[pageId].name)) {
  
          const tempObj = {
            name: dataObj.pagesAndArtboards[pageId].name,
            icons: []
          };
  
          for (const ab in dataObj.pagesAndArtboards[pageId].artboards) {
            if (dataObj.pagesAndArtboards[pageId].artboards.hasOwnProperty(ab)) {
              tempObj.icons.push(dataObj.pagesAndArtboards[pageId].artboards[ab].name);
            }
          }
          tempObj.icons.sort();
          customObj.categories.push(tempObj);
        }
      }
      fs.writeFileSync(`${dest}/metadata.json`, JSON.stringify(customObj, null, 4), 'utf-8');
      swlog.logSubEnd(thisTaskName);
      resolve();
    });
  }
docs: Get the metadata from the sketch file to map
  icons names to page names
  @param {String} src - The source of the sketch file
  @param {String} dest - The destination
  @returns {Promise}