Check ultrasonic range finder on multiple environments

[SaarYogev]

The last measurements produced weird results, with a fixed error of 4-8%(!), but of 0.05% when average error for that distance was subtracted. This may indicate 2 things:

1. The sensor has a fixed error that we can always subtract and get an extremely accurate result 👍
2. The error changes from time to time and is unknown, so we are unable to measure accurate distance with it at all 👎

this job needs to be done by a dedicated peroson, but not one experienced in those measurements. @Cookiemanthecookie @TalOrlanczyk assign yourself and tell me when you're ready.