Add integration_type hub to drop_connect (home-assistant#158932)

Author: joostlek

homeassistant/components/drop_connect/manifest.json

@@ -5,6 +5,7 @@
   "config_flow": true,
   "dependencies": ["mqtt"],
   "documentation": "https://www.home-assistant.io/integrations/drop_connect",
+  "integration_type": "hub",
   "iot_class": "local_push",
   "mqtt": ["drop_connect/discovery/#"],
   "requirements": ["dropmqttapi==1.0.3"]