graph: new package: example graphs
Created by: kortschak
Add a new package of example graphs for testing and demonstration.
Proposed in https://github.com/gonum/graph/pull/44#discussion_r30096838.
Created by: kortschak
Add a new package of example graphs for testing and demonstration.
Proposed in https://github.com/gonum/graph/pull/44#discussion_r30096838.