No reproducible results with multiple timepoints with option culture

[fraterenz]

./target/release/ecdna simulate --culture --cells 100 --sizes 100 100 100 100 100 --samples 40 40 40 40 40 --run s 1 --rho1 1 --distribution results/distributions/20copies.json --dynamics nplus nminus mean --patient bug_mean3timepoints does not give reproducible results.

I think that may be due to #62 and #66.

[fraterenz]

use next_u32 method of the rng with:

./target/release/ecdna simulate --culture --cells 10000 --sizes 10000 10000 10000 10000 --samples 100 100 100 100 --runs 1 --rho1 2.8 --dynamics nplus nminus mean --patient test_seed/f28 --savedir $HOME/ecdna-results/

twice renaming the first time. Then, plots and get the same plots