Ok, that works now, thanks. 
Fizzer - is it worth updating your test.yaml file also, to replace the tabs with spaces?  (Mine failed, complaining about "\t" until I did this).
Here is the tournament page:  
https://warlight001.appspot.com/
I am just messing about at the moment.  Will produce something 'useful' sometime soon.
---------------
Fizzer, a few questions/observations/comments ...
(1) Do you intend to work on this more?  Naturally I would like to stay close to your code, because then I benefit from your improvements...  or should I stick my code somewhere like github, to share the things I add?
(2) Seems I can only make 1 tournament at a time.  And new tournaments delete the old ones?  (or, you have to make more instances of your google apps pages, of which you have a limited number).
(3) How do I invite people, and also stop others from joining?  Can't anyone visit my webpage and generate an invitation?  Or do I just get that impression because all my dummy players come from the same computer?
(4) When I first start the webpage, and am faced by the 'start tournament' /start page - could another person jump in ahead of me and make that tournament?
(5) You prefer tabs over spaces for python indentation? :/
(5) Seems I need to know a bit of html also - in order to eg sort the players by rank, etc. - not a bit deal, but it isn't (quite) all in python (doesn't bother me, but it might be tough for the hordes of enthusiastic people learning python...  :)
(finally)  Nice that you have made this stuff, thanks.  My comments are meant to be constructive, not critical :)