Add spec file for SUSE build

This spec file is suitable for building calamari-server on
build.opensuse.org without using vagrant, i.e. we rely on the build
service to ensure we have a sane, clean build environment.

Note that this approach requires all runtime dependencies to be packaged
as RPMs (see Requires list in spec file), and most everything is
installed globally (e.g.: python stuff in the site python directory),
with only a few thins remaining in /opt/calamari.  These remaining
/opt/calamari pieces should eventually be moved to /etc or /usr/share.

Signed-off-by: Tim Serong <tserong@suse.com>