Offer of help... #1

Hello. I was looking for a node2vec implementation in Java, and I found your repo. I noticed that this was probably written by a developer that isn't as familiar with Java. I am beginning to refactor this, and make it more java-like. Would you be interested in a merge request to update this repository? Besides some stylistic things, there is some behavior that probably operates differently than you expected, and I will fix that stuff, too. Just let me know.