Add minimum spanning tree algorithm

[bobluppes]

It would be nice to add an algorithm to compute the minimum spanning tree of a graph. Two possible implementations here are Prim's algorithm and Kruskal's algorithm. Both implementations are valid candidates and could be added under this issue:

• Prim's algorithm (@derekjtong)
• Kruskal's algorithm (Add minimum spanning tree algorithm #22)

The implementation should go under src/graaflib/algorithm/minimum_spanning_tree.h. Each implementation should be covered with unit tests and should have it's public interface documented with javadoc-style comments.

[derekjtong]

Hi may I please be assigned this?

[bobluppes]

Hi @derekjtong, of course! There is already a PR open for Kruskal's algorithm, but do you want to work on Prim's?

[derekjtong]

@bobluppes Sounds good, I will work on Prims

[bobluppes]

Hi @derekjtong, closing this issue as I have split it into #51 and #52. Please comment on either of the new issues if you still want to pick this up.