DataFrame has an undeclared dependency on DataFrame-Math

[jecisc]

DataFrame has a dependency on DataFrame-Math but this is not declared in the baseline.

We could declare it in the baseline but I think it is better to just merge the two packages because DataFrame-Math contains only 2 classes with 1 method each and do not bring any new dependency.

[olekscode]

@jecisc Math is just a tag of the DataFrame package. It has two tags: Core and Math
Do we need to add dependencies for tags?

If yes, I suggest that we merge them