[modules/cpu] Add initial version of CPU utilization module

Re-enable the CPU utilization module as proof-of-concept for the new
core engine.

see #23

tests/modules/test_cpu.py

@@ -0,0 +1,16 @@
+# pylint: disable=C0103,C0111
+
+import unittest
+
+from bumblebee.modules.cpu import Module
+from tests.util import assertWidgetAttributes
+
+class TestCPUModule(unittest.TestCase):
+    def setUp(self):
+        self.module = Module(None)
+
+    def test_widgets(self):
+        widget = self.module.widgets()
+        assertWidgetAttributes(self, widget)
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4