fix Int32 random method generation with passed range into it

[azakordonets]

Upper bond cannot be less the lower bond. Added unit tests as well.

[thellimist]

I think this is a Swift 3 change. Could you add the necessary checks and tests as well?

https://github.com/azakordonets/SwiftRandom/blob/026db916dc668c5bd9ca978b1252d322820389f3/SwiftRandom/Randoms.swift#L21-L27

Thanks

[azakordonets]

Done