K-Cup Holder Suitable for printing on Printrbot Simple Metal

I liked the design of the original, but the first ring was over sized for printing on the Simple Metal even with no skirt, so I made some modifications.

1. The base now requires much less material, cut out some feet instead of a large circle. Also cored out a large portion of the the interior that wasn't needed. This shaved off about _33%_ of the print time.

2. The first ring also had a fair amount of material shaved off. The ring shrunk inward to be printable on a SM and some holes were