Fixed a bug which causes the server to crash when a player that wasn'y in a room disconnected.

.eslintrc.js

@@ -29,6 +29,7 @@ module.exports = {
         "semi": [
             "error",
             "always"
-        ]
+        ],
+				"no-mixed-spaces-and-tabs": "off"
     }
 };

src/index.js

@@ -31,8 +31,9 @@ app.get("/", (req, res) => {
 io.on("connection", (socket) => {
   // Handle disconnection
   socket.on("disconnect", () => {
+		
+    if (players[socket.id]) {
 	    const room = players[socket.id].room;
-    delete players[socket.id];
 
     	var playerUpdate = {};
     	if (io.sockets.adapter.rooms[room]) {
@@ -48,6 +49,9 @@ io.on("connection", (socket) => {
     	if (io.sockets.adapter.rooms[room] == undefined) {
       	console.log(traffic.int + colours.room(`Room ${room} has been deleted due to a lack of players`));
     	}
+    }
+
+    delete players[socket.id];
   });
 
   // Request identification