minimum version and non-semantic versioning (netCDF4)

[mathause]

We currently pin netCDF4 to version 1.5. However, I think netCDF4 does not really follow semantic versioning, e.g. python 2 support was dropped in version 1.5.6. So they may actually be doing something like 1.major.minor[.patch] - I asked about their versioning scheme in Unidata/netcdf4-python#1090.

So I wonder if we would need to pin netCDF to version to version 1.5.4.

[mathause]

1.major.minor sounds about right.

See Unidata/netcdf4-python#1090 (comment)

Notes

• Currently netcdf4=1.5 is required which would imply version 1.5.6. However, due to deprecate pynio backend #4491 version 1.5.3 is currently tested in ubuntu-latest py37-min-all-deps.
• ci/min_deps_check.py is written for the format major.minor.patch so this is currently not written for this scenario