importer: allow configuring a target git repository for an importer
importer: allow configuring a target git repository for an importer

Different importers can be run so that one importer only processes
some projects.  Because each importer will have a different public key,
if one importer picks the wrong project the push phase will fail.
The simplest way to support this configuration is to pass the target github
repository (or a prefix, for example git@github.com:somegithubuser)
to the importer via the Ansible config file, and from there
to patchew-cli and then to applier-get.

The applier-get API will then filter projects according to their git.push_to
property, and only return projects that match that property.

Signed-off-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>

patchew-project/patchew,patchew-project/patchew,patchew-project/patchew,patchew-project/patchew