Implement resistance distance and associated centralities

[szhorvat]

References:

https://en.wikipedia.org/wiki/Resistance_distance

https://mathematica.stackexchange.com/a/193130/12

https://mathematica.stackexchange.com/a/195039/12

https://networkx.github.io/documentation/networkx-1.9/reference/algorithms.centrality.html#current-flow-closeness

http://mathworld.wolfram.com/KirchhoffIndex.html