ffdc: Set PyYAML version requirement to >= 5.3.0
ffdc: Set PyYAML version requirement to >= 5.3.0

Set PyYAML earliest required version to 5.3.0 so code can run
on more installations without having to do unneeded update.
PyYAML 5.3.0 is selected for some of the fixes it provides.

Signed-off-by: Peter D  Phan <eac9d6da5208a55f31f482d8bf47ce1606742bda@us.ibm.com>
Change-Id: Ibac6e5ae26b74f635a6a1d1dd30787a6f0e58fba

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation