Output using the predict method in scikit-learn has changed in v1.1.0

The output format has changed such that y_pred, sigma = gp.predict(np.log10(freq[None, :].T), return_std=True) returns a sigma value that is 2-dimensional instead of 1-d. The temporary fix was to pin scikit-learn to version 1.0.2 or less. Should address this in the next release of pyDARM