Add hacking check for print() statements

Add hacking check for print() statements

We are frequently having to -1 patches because people
forget print() statements that were used for debug in
their development.  Can save everyone time and trouble by
adding this simple hacking check.

The check excluded the cinder/cmd directory as the files in there
legitimately need to use the print() command.  Also wsgi.py and
the test_hds_nas_backend.py files make use of print, so I have
excluded those from checking as well.

Change-Id: I2066eeb2bdc6c9af294d0b9befb7e0b32abd1378