DEPS: Increase minimum pandas version and remove old compatibility functionality

[datapythonista]

xref: https://github.com/ibis-project/ibis/pull/2450/files#r500471390

We are currently supporting pandas 0.21+, which was released in 2017. And we've got some functionality to support moved APIs in ibis/compat.py. We can increase the version of pandas, so that compatibility stuff is not needed anymore. Not sure what version of pandas is the minimum that has the new API that doesn't require that compat stuff, but that would be a good one to require as minimum.

[EdAbati]

/take

[EdAbati]

Hi @datapythonista ,

I did some digging and (if I understood correctly) it seems that all those functions and classes were moved in the current location in version 0.20:

• pandas.tseries.tools.to_datetime and to_time were moved to pandas.core.tools.datetimes in CLN: reorg pandas.tseries pandas-dev/pandas#16040
• pandas.types.dtypes.CategoricalDtype, DatetimeTZDtype and infer_dtype were moved in API: expose dtypes in pandas.api.types pandas-dev/pandas#16099 and CLN: move infer_dtype to pandas.api.types pandas-dev/pandas#16023

So I think we can just delete those lines in ibis/compat.py without increasing the minimum pandas version. What do you think?

[jreback]

yep sounds right