Slim Rostock Max v3 Fan for 713Maker Mounts

After upgrading to the 713Maker mount (http://713maker.com/mounts.html) for my E3Dv6, I found that the original slim fan shroud was too small. I remixed Noircogi's design to be both longer so it'll reach the print area, and added a gap in the middle of it to allow the PCB to sit in the gap. This results in a taller fan duct, and kind of works with autoleveling if you get them on straight and do a good job wiring. This is a WIP, as I would have brought the exhaust down lower but I didn't want to