Circuit Board Bumper With Clamp

I needed a bumper (base) for the ICSP circuit I made on [EasyEDA](https://easyeda.com/sej7278/icsp) so I designed this.

It has rounded outer corners and two notches along the inside to clamp the board down in the case so it won't move around.

Don't forget to allow for legs and solder when defining the height - for example FR4 is 1.6mm thick, but this needed almost 4mm due to some long legs on the headers.