Required Number of Covariates

[ErikKusch]

Hiya,

I just partook in a workshop organised by the IBS and am pretty stoked on your package here. Wanting to run an example as simple as possible during the workshop, I opted for a model with only two environmental covariates to my binary outcome of species-presence/absence.

Unfortunately, that caused a few issues in particular with the pd2bart function which seems to accommodate exclusively models with three or more covariates. I propose a check to be implemented in this function that alerts users to this fact.

Cheers,
Erik