add keyboard interrup exception.

cli_meter.py

@@ -77,11 +77,13 @@ def main():
         while True:
             #pdb.set_trace()
             update_reading()
+    except KeyboardInterrupt:
+        print("Keyboard Interrupt: quitting program.")
     except:
-        print("Error updating light reading.")
+        print("Error updating light reading...")
     finally:
-        print("clean up")
-        GPIO.cleanup() # cleanup all GPIO     
+        print("Cleaning up GPIO before closing...")
+        GPIO.cleanup()
 
 if __name__ == "__main__":
     main()