Motor mounts 1.0

A couple of motor mounts, one for 540 motors and one for 380 sized motors. The mounts have two holes through the bottom for zip ties. Some grooves in the bottom help epoxy grip the mount. They have a 5 degree slope to help line up the shafts. Print this with a fairly high fill, ~ 70%, to make sure they are strong enough to pull the zip tie tight.