Kubernetes e2e test encountered SSH error

[nilo19]

Error logs:

    Encountered SSH error.
    Unexpected error:
        <*errors.errorString | 0xc001a0ec60>: {
            s: "error getting signer for provider azure: 'GetSigner(...) not implemented for azure'",
        }
        error getting signer for provider azure: 'GetSigner(...) not implemented for azure'
    occurred

I consider to add the following configurations t docs/e2e-test.md:

export KUBE_SSH_KEY_PATH=path/to/ssh/privatekey
export KUBE_SSH_USER={ssh_username}