Update to Vagrant 1.9.8.
Remove Nokogiri dependency.
Use current vagrant-spec.
Use unrestricted version for rubygem(rspec) BuildRequire (RSpec 3 as of now).
Add rubygem(rspec-its) BuildRequire.
Backport use-system-certificates into standalone patch(from 630247626bf1353c463184f1bca6c59a246d33e2).