[MRG] Locality Sensitive Hashing for approximate nearest neighbor search(GSoC)

Nobody would run LSH on an index of 10 or 100 samples. Please start at 1e3 and add a point for 1e5. It's better written as:

n_samples_values = np.logspace(3, 6, 4).astype(np.int)  # 4 steps from 1e3 to 1e6