np.bool is deprecated

[hubgrim]

np.bool should be bool in this line, according to an error it throws calling this code:

    # generate dataset
    X, y = mglearn.datasets.make_forge()
    # plot dataset
    mglearn.discrete_scatter(X[:, 0], X[:, 1], y)
    plt.legend(["Class 0", "Class 1"], loc=4)
    plt.xlabel("First feature")
    plt.ylabel("Second feature")
    print("X.shape: {}".format(X.shape))
    plt.show()

[amueller]

Should be fixed in the newest release on pypi, can you try?