rewrite plugin checks to use ridley

[majormoses]

In order to support chef 13 we need to switch out chef/rest with ridley as it was removed (currently just deprecation warnings). An alternative is chefapi but this is not stable yet.

• check-chef-node.rb
• check-chef-nodes.rb

[majormoses]

I do think that we should move the client connection logic into a library module as it is the same in the 2 checks above as it would be in the handler which already uses ridley.

[majormoses]

Closing this out for the moment. would love to move all the connection logic into a lib but I just don't see me having the bandwidth as I want to start going around to all the plugins and start adding ruby 2.4 support which will be time consuming.