(MODULES-3958) use rspec-mock and add coverage

spec/spec_helper.rb

@@ -1,3 +1,7 @@
+RSpec.configure do |c|
+  c.mock_with :rspec
+end
+
 require 'puppetlabs_spec_helper/module_spec_helper'
 require 'rspec-puppet-facts'
 
@@ -34,6 +38,7 @@ RSpec.configure do |c|
   end
   c.filter_run_excluding(bolt: true) unless ENV['GEM_BOLT']
   c.after(:suite) do
+    RSpec::Puppet::Coverage.report!(0)
   end
 end