Bootstrapping an etcd database

List of default resources grows. We need to introduce bootstrap process for default Krake resources into the etcd database.
Current defaults:

default-roles:
- metadata:
    name: system:admin
  rules:
  - api: ""           # Empty string refers to all APIs
    namespaces: [""]  # Empty string refers to all namespaces
    resources: [""]   # Empty string refers to all resources
    verbs: ["create", "list", "get", "update", "delete"]

default-role-bindings:
- metadata:
    name: system:admin
  users: ["system:admin"]
  roles: ["system:admin"]