18650 cell holder longmon mount

This was designed to solve an issue I was having with mounting a longmon to the side of a cell block. I also wanted to join 2 blocks together in a stack. this fits my cell holders in a 5x4 x2 configuration. I've added notches to interlink with the longmon and hold it in place with out the possibility of over tightening the tie and snapping the longmon. Also added 2 additional side slots for additional configurations to tie blocks together for top and bottom should you need it.