PSO doesn't return solutions in order

[TimothyRogers]

Solutions returned from particle swarm optimiser are not in order of quality.

[MDCHAMP]

Just needs a commit adding something like

return sorted([ p.as_sol() for p in pop ], key=lambda p: p.fitness)

I'm not a GH power user enough to know how to commit to your branch <- caveman brain

I've added the line for PSO but still need to add something similar for the KrillHerd <- big brain

[MDCHAMP]

Closed with 4946aec