Refactor credit risk to use wave-ml

[vopani]

Using Wave ML

Bare minimum refactoring to use wave-ml for modelling. There is more that can be done but this is a good place to start.
Part of #41

Have tested this locally ✅

cc: @mtanco @geomodular

[vopani]

@mtanco This is ready to be merged. Things to note:

• Wave ML uses H2O-3 AutoML for modelling. Currently runtime set to 30 seconds - You can change this here

• Doesn't use validation split nor does cross-validation (didn't find it necessary) but I could add it if required.

• Models enabled are DRF, XGBoost and GBM. This is to ensure the local shapley contributions are supported.

[mtanco]

@vopani : @g-eoj has refactored this in another branch to use native wave plots
@g-eoj : @vopani has refracted this here to use wave-ml instead of native h2o-3

Can you two make sure both of your PRs merge nicely, as both of these are needed for our users but there is some overlap. Thank you!!

[vopani]

Please merge @g-eoj 's code first and I will redo the WaveML part, it should be simple.

[g-eoj]

@vopani my PR is merged

[vopani]

Ooopps, deleted by mistake. Opened a new PR here: #65