… inf

…population of a single individual, in which case we should assign a distance of 'inf' to indicate it has no neighbors. We also return the population that was given since the sorting mechanism may yield empty lists, which is what we were previously returning.

…vidual populations

…needs-to-handle-single-individual-pops

Also skip nan range objectives, which are degenerate if fitnesses are inf

…-to-handle-single-individual-pops' into 317-crowding-distance-calc-needs-to-handle-single-individual-pops

…e-single-individual-pops

… a single threaded worker. Hypothesis was that there were too many workers spun up by default that consumed too many resources. Besides, we only need a single worker given the nature of the distributed unit tests.

…-to-handle-single-individual-pops' into 317-crowding-distance-calc-needs-to-handle-single-individual-pops