Make focal the default framework
This MR makes focal the default base OS, after focal-based OTA 1 is out.
In addition:
- fixes makefile test target (
--cov
is not a cli argument anymore) - removes unaccessible custom log file feature that doesn't make sense for 20.04 anyways
- adapts unit tests to focal
Contributes to #277 (closed).
Edited by Jonatan Hatakeyama Zeidler