Fixed acceptance spec and add debian nodeset

spec/acceptance/apt_spec.rb

@@ -217,10 +217,7 @@ describe 'apt class', :unless => UNSUPPORTED_PLATFORMS.include?(fact('osfamily')
       end
 
       describe file('/etc/apt/preferences') do
-        it { should be_file }
+        it { should_not be_file }
-        it 'is managed by Puppet' do
-          shell("grep 'Explanation' /etc/apt/preferences", {:acceptable_exit_codes => 0})
-        end
       end
     end
   end

spec/acceptance/nodesets/debian-73-x64.yml

@@ -0,0 +1,11 @@
+HOSTS:
+  debian-73-x64:
+    roles:
+      - master
+    platform: debian-7-amd64
+    box : debian-73-x64-virtualbox-nocm
+    box_url : http://puppet-vagrant-boxes.puppetlabs.com/debian-73-x64-virtualbox-nocm.box
+    hypervisor : vagrant
+CONFIG:
+  log_level: debug
+  type: git