There is a way to have the Avatar images automatically generated, and you save them and set them on each user via Settings --> Users --> Users the way you would any other image:

• visit http://codepen.io/leecrossley/pen/CBHca

• enter the user's first and last name in line 3 of the JS box (the third box)

• right click the image that is rendered below the boxes and save it

• edit the user image (below) and set it to the newly created image

Example: