Version bump to v1.7.1

Revert role change from cluster-admin->system:persistent-volume-provisioner

gvisor fixes for v1.7.0

Create directory using os.MkDirAll, as mkdir -p does not work on windows

Remove pod list stability double check

Use cluster-dns IP setup by kubeadm

Skip driver autodetection if driver is already set

Customizing host path for dynamically provisioned PersistentVolumes

Fix lint error in start.go

Update kubeadm api version from v1beta1 to v1beta2

Use profile name as cluster/node name

Removed hardcoded `cluster-dns` IP 10.96.0.10, this allows kubelet to use `clusterDNS` configured by kubeadm in `/var/lib/kubelet/config.yaml`

Tested by starting minikube with `--service-cluster-ip-range=100.64.0.0/13` and verifying DNS resolution works.

/etc/systemd/system/kubelet.service.d/10-kubeadm.conf
```
[Unit]
Wants=docker.socket

[Service]
ExecStart=
ExecStart=/var/lib/minikube/binaries/v1.17.0/kubelet --authorization-mode=Webhook --bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --cgroup-driver='cgroupfs' --client-ca-file=/v
ar/lib/minikube/certs/ca.crt --cluster-domain=cluster.local --config=/var/lib/kubelet/config.yaml --container-runtime=docker --fail-swap-on=false --hostname-override=minikube --kubeconfig=/e
tc/kubernetes/kubelet.conf --node-ip=192.168.64.7 --pod-manifest-path=/etc/kubernetes/manifests

[Install]
```

DNS resolution test
```
kubectl run -i --tty --rm busybox --image=busybox --restart=Never -- sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes.io
Server:		100.64.0.10
Address:	100.64.0.10:53

Non-authoritative answer:
Name:	kubernetes.io
Address: 147.75.40.148
```

Fixes: https://github.com/kubernetes/minikube/issues/5727

fix lint errors

update releases.json to include v1.7.0

Set GOPATH for the entire release script

Add Azure PR to CHANGELOG

improve "docker-env" command to point to correct docker

Add Azure Container Registry support

Version bump to v1.7.0