This a standalone script that will look into a compose and create
unified ISO for each architecture. The ISO contains RPM repositories for
all variants that have the arch.
* The filename does not respect settings. This is tricky because the
name could include variant name, which we don't have here (by design
of unified ISO).
* The same is true for volume id.
In order to test the feature without running actual compose, we need to
add essentially a big chunk of compose. Most of the files are empty, as
their content is never accessed.
Signed-off-by: Lubomír Sedlář <email@example.com>