--auth-proxy
This implements --auth-proxy for serve s3. In addition it: * add listbuckets tests with and without authProxy * use auth proxy test framework * servetest: implement workaround for #7454 * update github.com/rclone/gofakes3 to fix race condition
Use like this (eg in cmd/serve/sftp) go test -v -run TestSftp/Normal -sub-run "TestIntegration/FsMkdir/FsPutFiles/FsDirMove"