Fix tests that fail with SELinux enabled

After the introduction of the `:lookup` symbol as the default value of the
SELinux-related properties of the file resource, some tests now fail because
they expect the file resource to not have properties with such behaviour. This
commit disables SELinux for such tests. Note that the failures occur only when
the tests are executed on systems with SELinux enabled (e.g CentOS).

Author: eciii

spec/unit/resource/catalog_spec.rb

@@ -21,6 +21,11 @@
   # audit only resources are unmanaged
   # as are resources without properties with should values
   it "should write its managed resources' types, namevars" do
+    if Puppet.features.selinux?
+      selinux = class_double('selinux', is_selinux_enabled: 0)
+      stub_const('Selinux', selinux)
+    end
+
     catalog = Puppet::Resource::Catalog.new("host")
 
     resourcefile = tmpfile('resourcefile')

spec/unit/transaction/resource_harness_spec.rb

@@ -29,6 +29,11 @@
 
   describe "when evaluating a resource" do
     it "produces a resource state that describes what happened with the resource" do
+      if Puppet.features.selinux?
+        selinux = class_double('selinux', is_selinux_enabled: 0)
+        stub_const('Selinux', selinux)
+      end
+
       status = @harness.evaluate(@resource)
 
       expect(status.resource).to eq(@resource.ref)