test/py: avb2.0: add tests for avb commands

1. Run AVB 2.0 full verification chain, avb verify
2. Check if 'avb get_uuid' works, compare results with
'part list mmc 1' output
3. Test `avb read` commands, which reads N bytes from a partition
identified by a name

Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
1 file changed