Implement caching of API responses including setting to prefer cache to avoid api requests

plejd/config.json

@@ -1,6 +1,6 @@
 {
   "name": "Plejd",
-  "version": "0.5.1",
+  "version": "0.6.0-dev",
   "slug": "plejd",
   "description": "Adds support for the Swedish home automation devices from Plejd.",
   "url": "https://github.com/icanos/hassio-plejd/",
@@ -18,6 +18,7 @@
     "mqttUsername": "",
     "mqttPassword": "",
     "includeRoomsAsLights": false,
+    "preferCachedApiResponse": false,
     "logLevel": "info",
     "connectionTimeout": 2,
     "writeQueueWaitTime": 400
@@ -30,6 +31,7 @@
     "mqttUsername": "str",
     "mqttPassword": "str",
     "includeRoomsAsLights": "bool",
+    "preferCachedApiResponse": "bool",
     "logLevel": "list(error|warn|info|debug|verbose|silly)",
     "connectionTimeout": "int",
     "writeQueueWaitTime": "int"