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

Please move that out of the loop: only call:

```python
X_all, labels_true = make_blobs(n_samples=max(n_samples_values), n_features=10,
                               centers=10, cluster_std=5, shuffle=True, random_state=0)
for n_samples in n_samples_values:
    X = X_all[:n_samples]
    ...
```