code: function generateIcons(sketchfile, dest) {
    return new Promise((resolve, reject) => {
  
      const startTaskName = swlog.logTaskStart(`build icons from ${sketchfile}`);
  
      if (!hasSketchtool()) {
        return reject('No sketchtool installed. Skipping create icons...');
      }
  
      Promise.all([
        createPagesMetadata(sketchfile, dest),
        createIconFiles(sketchfile, dest)
      ])
      .then(res => {
        const thisTask = swlog.logSubStart(`organize icon files`);
  
        const promises = options.iconFormats.map(format => {
          return sortByFileFormat(dest, format);
        });
  
        return Promise.all(promises).then(() => {
          swlog.logSubEnd(thisTask)
        });
      })
      .then(res => {
        resolve();
        swlog.logTaskEnd(startTaskName);
      });
    })
    .catch(swlog.error);
  }
docs: ------------------------------------- Main ------------------------------------- 
  Generate icons for a theme
  @param {String} sketchfile - The sketchfile source
  @param {String} dest - The destination path for assets
  @returns {Promise}