TODO
====

* **Check Authentication:** Nico reported that some endpoints
  even work without providing token. (ListUserVM)

* Put overrides for **IMAGE_BASE**, **VM_BASE** in **ImageStorageHandler**.

* Put "Always use only one StorageHandler"

* Create Network Manager
    * That would handle tasks like up/down an interface
    * Create VXLANs, Bridges, TAPs.
    * Remove them when they are no longer used.

* Check for :code:`etcd3.exceptions.ConnectionFailedError` when calling some etcd operation to
  avoid crashing whole application.
* Throw KeyError instead of returning None when some key is not found in etcd.
* Expose more details in ListUserFiles.