ultimaker 2 alu extrusion clone top corner bracket

This part regroups the 3 3D printed parts used on the top corner of the Ultimaker 2 Aluminum Extrusion 3D printer by jasonatepaint.

https://www.thingiverse.com/thing:811271

In order to make the frame even stronger merged the top and the 2 top side brackets into just 1 bracket.
I also increased the thickness of the bracket to 6mm all around and added 1 crew on all branches