Update Test Kitchen gem versions & remove old Vagrantfile.
Update Vagrant box URLs in .kitchen.yml & install latest omnibus pkg.
Add name attribute to metadata.rb, now required by Test Kitchen.
Support chef-solo and/or reading users from an attribute.

A new attribute (`node['znc']['users']`) will be used if the cookbook is
converged with Chef Solo or if the attribute is set to a truthy value
such as an Array. Otherwise converging with Chef Client will still use
the search by default preserving previous behavior.
Only signal znc process if process is running.

This prevents a failure where on initial converge, the
execute[force-save-znc-config] resource fails (service is not yet
running).
Wrap user hash user['znc']['modules'] in Array().
Merge branch 'solo-support' of https://github.com/fnichol/znc
Merge branch 'conditional-signaling' of https://github.com/fnichol/znc

Conflicts:
	recipes/default.rb
Merge branch 'arrayize-user-config' of https://github.com/fnichol/znc
Addressing CINK001
Addressing CINK002
Addressing Rubocop