Make cilium tests pass (#4660)

Cilium requires a high kernel. rhel7 and centos7 are too low, so they are removed.
Bumping ubuntu to ubuntu-1804

Change-Id: Ib1bffa45b8f9ed0ba500f751714372b3a3f7878b

tests/files/gce_centos7-cilium.yml

@@ -1,13 +0,0 @@
----
-# Instance settings
-cloud_image_family: centos-7
-cloud_region: us-central1-c
-cloud_machine_type: "n1-standard-1"
-mode: default
-
-# Deployment settings
-kube_network_plugin: cilium
-deploy_netchecker: true
-enable_network_policy: true
-dns_min_replicas: 1
-cloud_provider: gce

tests/files/gce_rhel7-cilium.yml

@@ -1,12 +0,0 @@
----
-# Instance settings
-cloud_image_family: rhel-7
-cloud_region: us-central1-b
-mode: default
-
-# Deployment settings
-kube_network_plugin: cilium
-deploy_netchecker: true
-enable_network_policy: true
-dns_min_replicas: 1
-cloud_provider: gce

tests/files/gce_ubuntu18-cilium-sep.yml

@@ -1,6 +1,6 @@
 ---
 # Instance settings
-cloud_image_family: ubuntu-1604-lts
+cloud_image_family: ubuntu-1804-lts
 cloud_region: us-central1-b
 mode: separate
 

tests/files/packet_centos7-cilium.yml

@@ -1,10 +0,0 @@
----
-# Instance settings
-cloud_image: centos-7
-mode: default
-
-# Kubespray settings
-kube_network_plugin: cilium
-deploy_netchecker: true
-enable_network_policy: true
-dns_min_replicas: 1

tests/files/packet_rhel7-cilium.yml

@@ -1,10 +0,0 @@
----
-# Instance settings
-cloud_image: rhel-server-7
-mode: default
-
-# Kubespray settings
-kube_network_plugin: cilium
-deploy_netchecker: true
-enable_network_policy: true
-dns_min_replicas: 1

tests/files/packet_ubuntu18-cilium-sep.yml

@@ -1,6 +1,6 @@
 ---
 # Instance settings
-cloud_image: ubuntu-1604
+cloud_image: ubuntu-1804
 mode: separate
 
 # Kubespray settings