HICTOP Y-Axis Belt Tensioner

This is a remix of this great [Y-Axis Belt Tensioner](http://www.thingiverse.com/thing:1302305) for Hictop printers. The two main differences are:
1. the legs width and height have been reduced (the original part had too big legs to fit my printer).
2. the bottom plate (under the nuts) is thicker to strengthen the weakest spot of the original part.