Allowing older version of pandas to be used

[cloudw]

As a common lib, it may be easier to have wide dependency ranges.

This PR is resolving a dependency conflict with zillow project using this repo:

There are incompatible versions in the resolved dependencies:
  pandas>=1.4.0 (from zdatasets[kubernetes]==0.2.1->-r requirements.in (line 9))
  pandas==1.3.5 (from floor-map-insights==1.3.9->panoloc==1.0.5->covis-pose==0.1.2->-r requirements.in (line 18))

[coveralls]

Coverage remained the same at 97.955% when pulling 4cc3c82 on yunw/relax_pandas_range into a5c58c1 on main.