I've created a 1.15.0 single-node kubeadm on a fresh installed Ubuntu 18.04.2 LTS. Then I deleted the cluster and recreated it. But now I can't recreate it anymore (I get etcd preflight-check error):

[init] Using Kubernetes version: v1.15.0
[preflight] Running pre-flight checks
    [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
error execution phase preflight: [preflight] Some fatal errors occurred:
    [ERROR DirAvailable--var-lib-etcd]: /var/lib/etcd is not empty

The commands that I've used are:

   # created a single node
    sudo swapoff -a
    sudo kubeadm init --pod-network-cidr=192.168.0.0/16
    mkdir -p $HOME/.kube
    sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
    sudo chown $(id -u):$(id -g) $HOME/.kube/config
    curl https://docs.projectcalico.org/v3.7/manifests/calico.yaml -O
    kubectl apply -f calico.yaml
    kubectl taint nodes --all node-role.kubernetes.io/master-
   # reseted a single node
    sudo kubeadm reset
    rm -fr .kube/
   # recreated a single node
    sudo kubeadm init --pod-network-cidr=192.168.0.0/16

Did I do something wrong?