PY3 fixed examples

examples/applications/plot_outlier_detection_housing.py

examples/applications/plot_stock_market.py

examples/bicluster/plot_spectral_biclustering.py

examples/bicluster/plot_spectral_coclustering.py

examples/cluster/plot_cluster_iris.py

examples/covariance/plot_outlier_detection.py

examples/ensemble/plot_forest_iris.py

examples/ensemble/plot_gradient_boosting_oob.py

examples/exercises/plot_cv_digits.py

examples/linear_model/plot_ols_ridge_variance.py

examples/linear_model/plot_ransac.py

examples/mixture/plot_gmm_classifier.py

examples/neighbors/plot_digits_kde_sampling.py

examples/plot_classification_probability.py

examples/plot_digits_classification.py