Standard should be implemented for NonZero types

[joshlf]

Now that the standard library NonZeroXXX types have been stabilized, Standard should support them.

[TheIronBorn]

In the meantime, this should work:

let distr = Uniform::new_inclusive(1, u32::max_value()); 
let sample = rng.sample(distr); 
NonZeroU32::new(sample)
// or
NonZeroI32::new(sample as i32)

[joshlf]

@TheIronBorn Cool, thanks!