Sync busted

[ryanfb]

We still don't want sync to actually sync changes back up to GitHub, which is controlled by git auth + having the canonical and github origins configured, but we do want sync to sync changes to the Numbers Server and Solr index.

Right now, this is broken because we only have one Postgres role/database for the editor named papyri with local trust auth, and no pn role /database for sync to store sync history. We may also need to create the sync_history table with the appropriate schema. So you'll see periodic errors e.g. FATAL: role "pn" does not exist