Updates required for tibbles

[ReasonableRadish]

Using the NetCDF() function and getting this warning to update tibble function references.

Looks like a simple swap of "as_data_frame()" for "as_tibble()" and "data_frame()" for "tibble()"

Warning messages:
1: as_data_frame() was deprecated in tibble 2.0.0.
ℹ Please use as_tibble() (with slightly different semantics) to convert to a tibble, or as.data.frame() to convert to a data frame.
ℹ The deprecated feature was likely used in the ncdump package.
Please report the issue at https://github.com/r-gris/ncdump/issues.
This warning is displayed once every 8 hours.
Call lifecycle::last_lifecycle_warnings() to see where this warning was generated.
2: data_frame() was deprecated in tibble 1.1.0.
ℹ Please use tibble() instead.
ℹ The deprecated feature was likely used in the ncdump package.
Please report the issue at https://github.com/r-gris/ncdump/issues.
This warning is displayed once every 8 hours.
Call lifecycle::last_lifecycle_warnings() to see where this warning was generated.

[mdsumner]

actually I think I fixed this a long time ago on github, I'll try a release

[mdsumner]

but, for what it's worth - I recommend using {ncmeta} instead of this package.