changed how efficiencies are updated: modified demand is now not recalculated (I think it is unnecessary to recalculate modified demand, since it is a measure of how "important" a connection is, and lines in lineCandidates shouldn't change the "importance" of a connection to the network, as lineCandidates lines aren't necessarily added to the network). Additionally, only the worst efficiency station pair is updated, and if the station pair is still the worst efficiency after the recalculation based on path, then choose it
fixed an issue with termination: previously if any line is shorter than minLength in targetEfficiencySatisfied(), the function returns false. Changed that to if any line is shorter than minLength, then the loop continues