Unrestrict rspec-* version to >= 3.5 to sync with vagrant
Unrestrict rspec-* version to >= 3.5 to sync with vagrant

Vagrant recently bumped its minimum rspec version to 3.10. This commit
unrestricts the version so that the requirements from old and new vagrant
versions can be accommodated.

electrofelix/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt,electrofelix/vagrant-libvirt,electrofelix/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt