Lab 02 solution mistake

[davidgonmar]

In Lab 02, the grad_norm_bound value in the last section is computed incorrectly. It should be calculated as (25 * np.linalg.norm(np.dot(A.T, A), 2) + np.linalg.norm(np.dot(A.T, b))) / A.shape[0] in order to use the Spectral Norm (not specifying the ord argument yields the Frobenius norm).