Introduce a 'stage_schema' fixture, which will load the stage schema
by the stage name defined in the STAGE_NAME defined in the test module
and optionally provided schema version and return it. If no schema
version is specified, version "2" is assumed. Modify all stage unit
tests to use this fixture, instead of loading the stage schema on their
own.
Signed-off-by: Tomáš Hozza <thozza@redhat.com>
2581160cfc