minor spelling fix
kmeans clustering implementation and simple tests
Merge branch 'master' of https://github.com/grafos-ml/okapi into kmeans_clustering
fixes bug with euclidean distance computation
added 2 more tests, using Stratosphere's KMeansDataGenerator
correct vertexID type in OutEdges
refactoring changes
deleted unecessary tests
Merge pull request #9 from vasia/kmeans_clustering

K-means clustering