`Random` instances for `Ratio`

There is currently no instances for `Ratio` data type that can give us random values

**Edit:** - It looks like we are in a agreement that `Uniform` and `UniformRange` instances are not possible for `Ratio`. Question then is, should we add a `Random` instance, which doesn't really promise uniformity?

I can see a reasonable `Uniform` instance for integral types, which excludes the zero denominator:

```haskell
instance (Integral a, Uniform a) => Uniform (Ratio a) where
uniformM g = do
n <- uniformM g
let notZero = do
d <- uniformM g
if d == 0 then notZero else pure d
(n %) <$> notZero
```

An efficient version for `UniformRange` needs some thought.

Note that neither `Uniform`, nor `UniformRange` would be able to generate `Rational`. This means that we can attempt and cook up such instance for `Random`