case for dust sensor SDS011 plus BME280 mount

I modified the [original case](https://www.thingiverse.com/thing:2530111) by [kleinerELM](https://www.thingiverse.com/kleinerELM).


#####Changes
* Added a pocket for a [4 pin style BME280](https://www.ebay.com/itm/253006151945) - may need a drop of glue for fastening the PCB
* Reduced the tube orifice to 9mm for a snug fit and removed it on the right side
* Reduced the bottom USB cable inlet
* Enlarged the weather protection shield on the left (+20mm)
* Moved the tube orifice 5mm to the rear side (not verified, see below)


#####What failed
* Added covers above the wall mount holes to make the rear side weatherproof - failed as the SDS011 needs this space - ripped them out and closed the wall mounts with Bondic UV adhesive. Thus they were removed from the model. If you decide to add them again keep in mind to move everything inside up as much as those covers may consume in height.
* Added a perforated cylinder between the left weather protection shield and the air inlet w