```release-note:improvement
deps: Update hashicorp/raft-boltdb to v2.2.0
```

```release-note:improvement
agent: Switch from boltdb/bolt to go.etcd.io/bbolt
```

```release-note:improvement
core: Enable configuring raft boltdb freelist sync behavior
```

```release-note:improvement
metrics: Emit metrics regarding raft boltdb operations
```

```release-note:breaking-change
agent: The state database on both clients and servers will automatically migrate its underlying database on startup. Downgrading to a previous version of an agent after upgrading it to Nomad 1.3 is not supported.
```