add integration test for group

test/integration/default/group_spec.rb

@@ -0,0 +1,32 @@
+# encoding: utf-8
+
+# test root group on linux
+if os.linux?
+  describe group('root') do
+    it { should exist }
+    its('gid') { should eq 0 }
+  end
+
+  describe group('noroot') do
+    it { should_not exist }
+    its('gid') { should eq nil }
+  end
+end
+
+if os[:family] == 'freebsd'
+
+  describe group('wheel') do
+    it { should exist }
+    its('gid') { should eq 0 }
+  end
+
+  describe group('root') do
+    it { should_not exist }
+    its('gid') { should eq nil }
+  end
+
+  describe group('noroot') do
+    it { should_not exist }
+    its('gid') { should eq nil }
+  end
+end