Mixin Avatars

Hey guys! I have finished the avatar mixin. let me know if this works for you. Aso fixed a typo on my name in the footer - no biggie!
Now that I am looking at the code changes - notice lines 120, 139, 158. Dan - now sure about it but if you see the difference. I am calling in 120 (just the css class name through the mixin). In lines 139 and 158 I call the image in both HTML src tag AND in the CSS class name. Shouldn't we just have it being called from the css? Let me know and I will change it.