Define apt keys as files
- jobs/templates/debian: Create "keys" folders out of a template directory
- jobs/templates/debian: Remove unnecessary (<- maybe?) read/write operations
- jobs/templates/debian: Add wrapping ls command to ensure it works
This to allow a simple update of apt keys later on (the current need is to update the cassandra apt keys)
Test Plan
tox
Well and then aside pushing and installing this on jenkins, i don't know how to check that it actually works...
Migrated from D3109 (view on Phabricator)