Ravel v0.0.3 Ravel.Rules.Present
iex> Ravel.Rules.Present.validate nil, %Ravel.Rules.Present{}, :field, [] false
iex> Ravel.Rules.Present.validate 5, %Ravel.Rules.Present{}, :field, [field: 5] true
iex> Ravel.Rules.Present.validate “”, %Ravel.Rules.Present{}, :field, [field: ""] true