simple_random_providers

create the default random provider depending on the environment settings

name of env var to provide default random seed.

If set, this u64-value will be used too seed the default random number generator.
If not set, the default random number generator will be time seeded.

If set to unparsable number, panic on installation of the default random
number generator.

create a time-seeded simple provider for pseudo random numbers that are not safe
for security and that do not meet typical requirements for a good
random number generator.

create a time-seed sprovider for pseudo random numbers that are not safe
for security and that do not meet typical requirements for a good
random number generator.