Create "fuzz" helper for kitimat-jest

This function would be the "snapshot testing" of property-based tests - don't want to use much effort and just have something that does a general sanity check that the function won't throw.

```ts
import { integer } from 'kitimat-jest';

fuzz('my func doesn\'t throw', [integer()], int => myFunc(int));
```

Maybe this should also try to throw garbage and see that there is an exception if the wrong type is passed.