Update deps

[kkuehlz]

cc @aekeus no longer WIP and ready for review. This bumps hapi and joi to the latest versions, refactoring as needed.

[kkuehlz]

Differences from https://github.com/brave/vault-updater/tree/upgrade-to-latest-hapi

• Updates joi (required by latest version of hapi)
• for routes, uses options instead of config (more idiomatic)
• Leaves mongo driver version
• Doesn't await in usage pings, because this was possibility causing perf regressions

[kkuehlz]

@aekeus This is rebased with master and good to be reviewed.