Decide on save game format

[jbheard]

How should we go about saving the game to a file?

I think that pickling the data could be good, but since the data will be from a user (i.e. no guarantee it comes from our program), pickle might not be a good choice for security reasons.

We could probably dump it into a yaml file, but then it is very easy for users to cheat
(providing their own values), and it could require some extra work to set up the file format.

[jbheard]

Is it possible to calculate an HMAC and/or encrypt the pickled data?
I think this would require some kind of secret, which would be less than ideal (imagine needing a password to access your game saves).