Fixed a bug about the impression vector creation in KDDCUP data set.
Merge branch 'origin/master'

Conflicts:
	workspace/ParallelMAB/src/edu/fiu/cs/kdrg/parallelmab/data/SparseVector.java
	workspace/ParallelMAB/test/edu/fiu/cs/kdrg/parallelmab/model/recommender/KDDCUPDataRecommenderTest.java