Make rpmbuild module work on non-RPM based GNU/Linux systems

[vutny]

What does this PR do?

Allows to build rpms and make YUM repositories on Debian operating systems.

I've successfully built rpm package and created a repository on Debian machine by installing the required tools using this sls:

Install rpmbuild tools:
  pkg.install:
    - pkgs:
      - createrepo
      - mock
      - python-gnupg

What issues does this PR fix or reference?

None.

Previous Behavior

The rpmbuild execution module doesn't load on Debian GNU/Linux minion.

New Behavior

The rpmbuild execution module and pkgbuild state works on Debian.

Tests written?

No

[thatch45]

We can't take this because it will cause an error with the Debian package build module, this will cause the Debian and the redhat pkgbuild modules to collide since they abstract a virtual interface. If you return the string 'rpmbuild' then it will be ok.

[vutny]

Thank you @thatch45 !

Indeed, I haven't thought that if all dependencies met for both debbuild and rpmbuild modules there would be a collision.
Also, it seems that you could build RPM packages "natively" not only on RHEL clones, but on Suse Linux as well, which is RPM-based OS. So rpmbuild should be exposed as virtual module pkgbuild on Suse. I haven't tested it, but I see no problem here, tools are the same.

On the other hand, rpm packages and repositories potentially could be created on any other non-RPM based GNU/Linux distro if you install necessary tools and Python module... In this case the __virtual__ function in rpmbuild.py module would return rpmbuild string instead of pkgbuild.

I've also changed pkgbuild state module, so it will call appropriate function from rpmbuild (virtual) module on non-RPM platforms if the one would provide RPM package as a result of pkgbuild.build state argument or a directory with *.rpm file in it to pkgbuild.repo state.

Please review my last commit.

[vutny]

Updated PR subj. Test failures seems not related to my changes...

[thatch45]

I don't make spelling mistakes as often as I used to, thanks!

[thatch45]

Masterfully done! Thanks!