future proofing is good, but...

since print() was made a function in py3, i can predict at some point
that return will be made a func as well. sure, good.
but "return()" *currently* returns an empty tuple. We want to
explicitly return None for testing purposes.

extras/genPSK.py

@@ -75,7 +75,7 @@ def main():
                           'Please ensure you have provided the correct passphrase.'))
     psk = pskGen(args.ssid, args.passphrase)
     print('PSK for network "{0}": {1}'.format(args.ssid, psk))
-    return()
+    return(None)
 
 
 if __name__ == '__main__':