Added switch_dim parameter to ChangePoints kernel by clwgg · Pull Request #1671 · GPflow/GPflow

@clwgg

This parameter allows to define the ChangePoint on one particular dimension of
the input space. All other dimensions are still available to the kernels being
switched, and can be selected via active_dims.
- move `ref_changepoints()` to reference.py
- move changepoint tests to test_changepoints.py

@clwgg

@clwgg

@clwgg