title: Mocking kernel release on ChefSpec
body: <p>I am trying to test that <code>linux-image-extra-#{node['kernel']['release']}</code> will be installed by my cookbook and I'm trying to mock up <code>#{node['kernel']['release']</code> using Fauxhai. So far I have;</p>
  
  <pre><code>    describe 'my-cookbook::recipe' do
        let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '14.04').converge(described_recipe) }   
  
        before do
              Fauxhai.mock(platform: 'ubuntu', version: '14.04') do |node|
                node['kernel']['release'] = '3.13.0-66'
              end
            end
  
          it 'installs linux extra image package do'
              expect(chef_run).to install_package("linux-image-extra-#{node['kernel']['release']}-generic")
          end
      end
  </code></pre>
  
  <p>Unfortunately It isn't picking up the attribute and is producing an error that shows this;</p>
  
  <blockquote>
    <p>Failure/Error: expect(chef_run).to
    install_package("linux-image-extra-#{node['kernel']['release']}-generic")</p>
  </blockquote>