Remove hpxml requirement for number_of_residential_units

[vtnate]

number_of_residential_units is required in the geojson file, possibly starting in HPXML v1.7.0. The check for this field doesn't need to exist as this information should be, and is, contained within the HPXML file itself. AFAIK there isn't any problem removing this check from the code.

[joseph-robertson]

Hi @vtnate. Are you able to point explicitly to the check you're referring to in this issue?

[vtnate]

Hmmm, good question. No, I can't find it now. That seems like a good indicator that this is a stale issue! I'll close and if it's a problem in the future we can sort it out then.