Raspberry Pi Zero EnviroPlus Stand Remix

A remix of the Raspberry Pi Zero EnviroPlus Stand to better fit my needs. The enviroPlusClip.stl is unchanged but included here for completeness. All credit to @jpwsutton for a simple and elegant design.

Changes made:

* Base is longer to prevent tipping back
* Base has a small shelf on the front to prevent tipping forward
* Cabling hole expanded to better accommodate larger USB cables
* Mounting holes for RPi moved up just a hair for better clearance for bolts that I had used to mount the PM sensor.

Update: an optional camera mount for this model and a mount for a full sized Raspberry Pi is available at https://www.printables.com/model/651598-vertical-stand-for-full-sized-rpi-with-optional-ca