test: Remove cilium DS before installing a new one
test: Remove cilium DS before installing a new one

Previously, when installing Cilium via "ciliumInstallHelm()", changes to
ConfigMap were not applied if Cilium DaemonSet had already been
installed.

An example of such occurrence in test logs:

    time="2020-02-01T21:01:58Z" level=debug msg="running command: kubectl apply --force=true -f cilium-15ef6310fc44caf0.yaml -n kube-system" cmd: "kubectl apply --force=true -f cilium-15ef6310fc44caf0.yaml -n
    kube-system" exitCode: 0 duration: 118.450977ms stdout:
    configmap/cilium-config configured
    serviceaccount/cilium unchanged
    serviceaccount/cilium-operator unchanged
    clusterrole.rbac.authorization.k8s.io/cilium unchanged
    clusterrole.rbac.authorization.k8s.io/cilium-operator unchanged
    clusterrolebinding.rbac.authorization.k8s.io/cilium unchanged
    clusterrolebinding.rbac.authorization.k8s.io/cilium-operator unchanged
    daemonset.apps/cilium unchanged
    deployment.apps/cilium-operator configured

Missing removal of the Cilium DS were causing some flakes, e.g. when
the test suite k8sT/external_ips.go was ran before k8sT/Services.go. The
former in some test cases were using `--device=enp0s9` instead of
`--device=enp0s8`, and k8sT/Services.go required the latter device
setting.

Signed-off-by: Martynas Pumputis <6b0d31c0d563223024da45691584643ac78c96e8@lambda.lt>

tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,cilium-team/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,cilium-team/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium