Splitting the add_or_update action down

Splitting the add_or_update logic out to allow add actions or update
actions to also be used.
Corrected converge errors

Added missing do to action :add definition and updated test recipe to
use boolean value in
lwrp.
Fixing Foodcritic FC039

Fixing foodcritic errors
Refactoring and fixing Chef Client 12 compatibility

Making use of Chef::Resource::OpsviewClient objects and ensuring
rest-client gem is installed since chef-client 12 no longer bundles
rest-client.
Merge pull request #2 from robcoward/Split_Action

Split actions to allow add and update as separate actions