start of work at L4
sorted list
Popular female names added.
Added top_k.
Added down_heapify.
Added more heap functions.
Better remove_min.
Added minimize_absolute. Now we find the median in theta(n) time.
Added mode.
Added up_heapify.
no message
Calculating actor centrality...
Added faster centrality.
Actor centrality done.
Actor centrality with other data sets.
Merge branch 'feature/L4' into develop