build-unit-test-docker: Add catch2 unit-test framework
build-unit-test-docker: Add catch2 unit-test framework

This test framework is similar to googletest, but much more c++11
friendly and supports sectioned test semantics that are much more ugly
to implement in googletest.

https://github.com/catchorg/Catch2/blob/master/docs/why-catch.md

Change-Id: Icd547ba54e372e1656df58418c0dd1c661ca5a8d
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/openbmc-build-scripts,openbmc/openbmc-build-scripts