Test if Beltzer package can be used to create GRIB idx files without downloading fill.

[blaylockbk]

Ok, so I saw this on LinkedIn and it would be super helpful for Herbie...

This python package would enable Herbie to subset data even when an index file isn't available for the file.

https://github.com/joxtoby/beltzer

[blaylockbk]

I installed it and it didn't work out of the box. But I'll keep an eye on this new package and incorporate it in Herbie if it seems helpful. (How quickly will it generate the idx file?)