Add example policies in policies

[cdstanford]

This is a follow-up issue to #7.
Once you have added a test crate, write a policy for the crate in policies/<crate name>.toml The policy should have the same name as the crate. You can look at the existing policies to see the expected policy syntax.

To check your policy against the crate: run

./scan.py -c <crate name> -t -p policies/<crate name>.toml

and look at the output. It should inform you of any effects found in the source code that are not noted in the policy. Report anything weird or errors that you find!

[cdstanford]

closing as obsolete