Add WebSockets library

.travis.yml

@@ -25,6 +25,7 @@ before_install:
     fi
   - arduino --install-library PubSubClient,PageBuilder:1.3.3
   - arduino --install-library ArduinoJson:5.13.5
+  - arduino --install-library WebSockets:2.1.1
   - buildExampleSketch() { arduino --verify --board $BOARD $PWD/examples/$1/$1.ino; }
   - arduino --install-library ArduinoJson:6.10.0
   - buildExampleSketch() { arduino --verify --board $BOARD $PWD/examples/$1/$1.ino; }

library.json

@@ -17,6 +17,10 @@
     {
       "name": "ArduinoJson",
       "version": ">=5.13.3"
+    },
+    {
+      "name": "WebSockets",
+      "version": ">=2.1.1"
     }
   ],
   "frameworks": "arduino",