Brings `tx_people` into the future. Was more concerned with getting it working for `tx_salaries` than doing anything super relevant to `tx_people`. Main changes:
- South is no more. Any migrations that run against this will need `--fake-initial` so Django recognizes that everything is chill.
- Adds some indexing to fields that are _killing_ `salaries.texastribune.org` right now during updates. We're talking **6 hour updates** turning into **45 minute** updates with this change.