Don't run ruby-spec for release tags
Don't run ruby-spec for release tags

ruby-spec is out of our control and it's failing on ruby-2.5.0.
It will be fixed with ruby-2.5.1, but now it blocks another pkgrel
of RubyInstaller.

larskanis/rubyinstaller2,larskanis/rubyinstaller2,oneclick/rubyinstaller2,oneclick/rubyinstaller2,larskanis/rubyinstaller2,oneclick/rubyinstaller2