Unsecure source of random numbers in pure rust

evilrng provides a unsecure source of cryptographical secure random
number and is written by an amateur for the sole purpose that he
learns a bit about cryptography.  It is very probably *very*
vulnerable, so **do not use evilrng** for real world cryptographical
purposes, but if you're just looking for a way to get non obvious
pattern based numbers and want to make sure that your programme won't
work on windows or will be not-GPL, you actually may use this one
evil\* crate.