Impossible to Re-implement #91
Description
After reading through your base.go file to re-implement the graph per the interface I realized that a lot of the ways you modify the vertices and edges are accessing private data that cannot be modified outside of the gograph package itself. For example, it is not possible to change the degree of a vertex as the provided functions only allow you to read them and not increment or reset them. The base file is already not thread safe so it could be that those values are exposed directly and rely on the implementation to provide the safety. Alternatively they could be exposed via getters/setters that perform atomic operations on them. I'm happy to put together either PR for you, just let me know what your preference is or if this is something you think would be valuable.