Add variable number of discriminator updates for each generator update

[Baukebrenninkmeijer]

As per WGAN, the discriminator should be updated 5 times more often than the generator. This is added as a parameter in the __init__ function.

Fixes #101

[CLAassistant]

All committers have signed the CLA.

[csala]

Thanks @Baukebrenninkmeijer It looks good!

I would make a couple of minor changes that I think will improve the overall result:

1. I would rename the parameter to something like discriminator_steps. Otherwise, at first sight someone may thing that n_discriminators=5 means "Use 5 different discriminators".

2. Providing some more context in the docstring would be helpful. I would add a sentence to explain what is the effect of increasing or decreasing the value, a link to the WGAN paper, and then mention that the default is 1 to match the original CTGAN implementation.

Would you mind adding these? Once it is done I think we are all set!

[Baukebrenninkmeijer]

@csala Done and done

[csala]

Looks good now! Thanks @Baukebrenninkmeijer !

[Baukebrenninkmeijer]

Some checks are not clearing due to unrelated requirements issues it seems.

@csala @fealho

[csala]

Some checks are not clearing due to unrelated requirements issues it seems.

Yes, sometimes there are random errors related to the Github Actions infrastructure. I'm re-running the tests.

[Baukebrenninkmeijer]

Hmmm a value count in the samples was too high. But that seems also unrelated with my changes. Is that bound maybe too tight? Its 6550isch when it should be below 6500.