[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

bumblebee/modules/cpu.py

@@ -0,0 +1,18 @@
+# pylint: disable=C0111,R0903
+
+"""Displays CPU utilization across all CPUs."""
+
+import psutil
+import bumblebee.engine
+
+class Module(bumblebee.engine.Module):
+    def __init__(self, engine):
+        super(Module, self).__init__(engine)
+        self._utilization = psutil.cpu_percent(percpu=False)
+
+    def widgets(self):
+        self._utilization = psutil.cpu_percent(percpu=False)
+
+        return bumblebee.output.Widget(full_text="{:05.02f}%".format(self._utilization))
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4