```
```
The flakes manifested as:
```
--- FAIL: TestV3WatchRestoreSnapshotUnsync (3.59s)
v3_watch_restore_test.go:82: inflight snapshot sends expected 0 or 1, got ""
FAIL
coverage: 55.2% of statements
FAIL go.etcd.io/etcd/v3/integration 3.646s
FAIL
```
The root reason is that all the SnapMsg processing happends on both ends
(leader, follower) assynchronously in goroutines, e.g. on Fifo schedule
within EtcdServer.run, so when we observe through metrics, we don't
know whether it finised (or even got started).
Idally we should have EtcdServer.Drain() call that exits when the server
processed or internal 'queues' and is idle.
This change makes the etcd package compatible with the existing Go
ecosystem for module versioning.
Used this tool to update package imports:
https://github.com/KSubedi/gomove
