Comparing the speeds of various Nim libraries for
arbitrary precision integers.

Test Targets:
https://github.com/status-im/nim-stint
https://github.com/nim-lang/bigints
https://github.com/michaeljclark/bignum
https://github.com/FedeOmoto/bignum
https://github.com/fsh/integers

Test algorithms:
https://en.wikipedia.org/wiki/Pollard%27s_rho_algorithm#Algorithm