Anet a8 mini voltmeter/amperemeter support

Support for mini voltmeter and amperemeter.
The two holes are a little bit more large to allow size variation with differents printers and mini volt/amp.
Here the links:
-mini voltmeter:
https://www.amazon.fr/voltm%C3%A8tre-testeur-num%C3%A9rique-voltage-batterie/dp/B00ESCNYB8/ref=sr_1_2?ie=UTF8&qid=1517320020&sr=8-2&keywords=mini+voltmetre
-mini amperemeter:
https://www.amazon.fr/SODIAL-Amperemetre-Testeur-Numerique-Courant/dp/B00LVP9AM2/ref=sr_1_2?s=hi&ie=UTF8&qid=1517320110&sr=1-2&keywo