Move inherits keyword from errors.yaml to metadata.yaml

The metadata.yaml file is the correct location for the inherits.
Update the elog-gen.py parser to support this change.

Change-Id: Iac7f67ec72e761ab3dafbf89c7e4d5495b34f00d
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
7 files changed