GoPro Session RunCam3 Mount for QAV-R 220

Changes from original model:
- front vertical stands are much thicker
- added some pads to hold camera side movements
- removed hole at the bottom; I dont think it saved any weight
- added two bumbers at the top edge

Notes on printing:
- print laying on the side. It will produce much more support material, but it will strengthen the mount very well. If printed as it will stand on quadcopter, it will de-layer on each severe impact.