New basis is missing

[kwinkunks]

There is code to accept a basis in well.df(), but it doesn't do anything.

E.g. lines 589 to 593 in well.py:

if basis is None:
    basis = self.survey_basis(keys=keys, alias=alias)
if basis is None:
    m = "No basis was provided and welly could not retrieve common basis."
    raise WellError(m)