Add rspec coverage output

- This checks which Puppet resources have been explicitly checked as
  part of the current test run and outputs both a coverage percentage
  and a list of untouched resources.

Change-Id: Ie273f5e4f3bbeb8dac52ab8ba5f09c5145a231c1
Signed-off-by: Gael Chamoulaud <gchamoul@redhat.com>

spec/spec_helper.rb

@@ -5,3 +5,5 @@ RSpec.configure do |c|
   c.alias_it_should_behave_like_to :it_configures, 'configures'
   c.alias_it_should_behave_like_to :it_raises, 'raises'
 end
+
+at_exit { RSpec::Puppet::Coverage.report! }