Download containers and save all

Move version/repo vars to download role.
Add container to download params, which overrides url/source_url,
if enabled.
Fix networking plugins download depending on kube_network_plugin.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/kubernetes/node/defaults/main.yml

@@ -8,9 +8,6 @@ kube_resolv_conf: "/etc/resolv.conf"
 
 kube_proxy_mode: iptables
 
-hyperkube_image_repo: "quay.io/coreos/hyperkube"
-hyperkube_image_tag: "{{ kube_version }}_coreos.0"
-
 # IP address of the DNS server.
 # Kubernetes will create a pod with several containers, serving as the DNS
 # server and expose it under this IP address. The IP address must be from

roles/kubernetes/node/meta/main.yml

@@ -1,5 +1,5 @@
 ---
 dependencies:
-  - role: download #For kube_version
-    file: "{{ downloads.nothing }}"
+  - role: download
+    file: "{{ downloads.hyperkube }}"
   - role: kubernetes/secrets