Limit population data to what we actually need #2340

This allow us to "save" 41'580 records
Drop extra data for geonames #2340

Limit extra data to avoid hydrating things that are never used
Pre-compute population for regions and world #2340

We avoid computing population on the fly for aggregation
for things that almost never change
Add world and questionnaireUsage to benchmarking #2340
Install redis on Travis #2340