Remove unused packages

* libv8 hasn't been used in a long time, we use the v8 SCL and packages now
* augeas hasn't been used since the core Puppet dependency was dropped
* i18n_data was removed in #7233
* ffi was added to EPEL7
* levenshtein is unneeded since gettext update in #7233
* rdoc4 is unused, perhaps since core Puppet dep was dropped
* shadow is unused, since core Puppet dep was dropped
Remove foreman-devel, foreman-test

The dependency tree is very out of date, even on Fedora, which is currently
the only OS it is built for (SCL was excluded already) and I don't feel it's
worth trying to maintain it.
Remove unused foreman-devel dependencies