Lint the uploaded zips

[PeterJCLaw]

Would be super-awesome to run linting against the uploaded archives, just like the IDE does.

[PeterJCLaw]

We've had a couple of teams who managed to submit broken code (including one which was a SyntaxError) for the first leagues, so it would be really great to have this.

[PeterJCLaw]

Extreme idea here: run a match of the robot against itself in CI and vend the recording back to the team for confirmation.

[PeterJCLaw]

A more minimal check we could use here would be to just validate that the code is valid Python, by compiling it to an AST. This is probably simpler to implement as we can do it all in memory and without an interesting dependencies. There's the small catch that the Python version the submitter runs as likely doesn't match the one used in the competition, but this would still catch a bunch of useful cases.