`--deterministic` flag should set a random seed for random processes

[kenibrewer]

As discussed in #509 in this comment, Flye still produces different assembly outputs when using the --deterministic flag. That is because multi-threading is not the only source of non-determinism. There is also the use of random variables in the process here.

An improved --deterministic flag should set a random seed for these other processes to allow the entire assembly process to occur deterministically.

A fully deterministic Flye would be very helpful for integrating Flye into bioinformatic pipelines that are tested against reference datasets.

[mikolmogorov]

Makes sense, will add this to the list of TODOs for the next release, thanks!