Updating observable on webscoket event

Change-Id: I8325785b8d40b646ea67f28b61b8d603803a571e
diff --git a/src/app/interfaces/instance.interface.ts b/src/app/interfaces/instance.interface.ts
new file mode 100644
index 0000000..29a37f2
--- /dev/null
+++ b/src/app/interfaces/instance.interface.ts
@@ -0,0 +1,6 @@
+export interface IInstance {
+  id: number;
+  name: string;
+  backend_status: string;
+  created: string;
+}