altmin and altmax are ignored parameters in the API

[sedv8808]

When passing a query requesting for sites between certain heights using altmax and altmin, only filtered results should come back.

However, all sites https://api.neotomadb.org/v2.0/data/sites seem to be getting a null elevation

Steps to Reproduce the Problem

1. Look at endpoint: https://api.neotomadb.org/v2.0/data/sites?altmin=100&altmax=300

Alternative

1. Look at any sites endpoint, all elevation fields are null

If we look in the database snapshots, there are sites that have the elevation field different than null