Bump compat for EnsembleKalmanProcesses for docs

[jagoosw]

EnsembleKalmanProcesses introduced a change in v0.2 which causes the data assimilation example to fail, I think it isn't an API issue but the fact that the default settings have changed to be "cutting edge" so we might need to take some more care in how the example is written, or manually set the previous defaults.