Use /nodes/ as the lock server endpoint

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Change default lock server to paddles

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Remove old lock server

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>