Amazon Echo Dot V2 Wall/Ceiling Mount

Brilliant original design by [halcyon](http://www.thingiverse.com/halcyon) can be found here - http://www.thingiverse.com/thing:1463045. I have had a lot of people ask for this to be printed and from their feedback I have updated it with some of my amends. These are as follows:

* Added countersunk screw holes for mounting (I did ask halcyon for this and he updated his design, but I went for a more traditional UK bevel screw).
* Moved the mount holes to line up with the USB/Audio holes - assuming cabled will run downwards/upwards from Echo Dot and gives a more secure mount if mounting into a wooden stud.
* Added contoured sloped grooves in base to deflect audio from speaker outwards (may/may not make any difference in sound?!!) and to reduce plastic filament.
* Added arches to speaker holes to reduce plastic filament use and to help reduce amount of bridging needed. Also looks nice!
* Added support column in middle of USB/audio hole to help with bridging the gap. I found the brid