OK, well if you are using 2.6.1-2 then the line you insert at the top of the pam module is
auth sufficient pam_python.so /lib/security/howdy/pam.py
If sudo howdy test works and you have added a face profile then all there is to do is modify the pam modules to suit your requirements.
The additional lines though need to be the first lines when the module is read.
Try uninstalling 2.6.1.-2 and add howdy-beta-git the install is more straightforward and add the correct line to your pam modules.
H