add evacuate struct to server (#185)

Author: mattoni

components/schemas/infrastructure/servers/Server.yml

@@ -57,6 +57,16 @@ properties:
   ephemeral:
     type: boolean
     description: Set to true when a server is created as part of an auto-scale event.
+  evacuate:
+    nullable: true
+    description: Details about a server's evacuation status. When an evacuation is in progress, no new container instances will be permitted on the server.
+    type: object
+    required:
+      - started
+    properties:
+      started:
+        description: The time when this server began evacuating instances.
+        $ref: ../../DateTime.yml
   state:
     $ref: "./ServerState.yml"
   events: