message: node demo runs now (no ppt yet though)
diff: @@ -101,8 +101,9 @@ else {
  // EXAMPLE 2: Use an inline callback function
  pptx.writeFile(exportName+'-ex2')
  - .catch(ex => { console.log('ERROR: '+err) })
  - .then(fileName => { console.log('Ex2 inline callback exported: '+fileName); } );
  + .catch(err => {throw err})
  + .then(fileName => { console.log('Ex2 inline callback exported: '+fileName); } )
  + .catch(err => { console.log('ERROR: '+err) });
  // EXAMPLE 3: Use defined callback function
  //pptx.save( exportName+'-ex3', saveCallback );
  