Added typescript types for socket.io to dependencies

package-lock.json

@@ -85,6 +85,15 @@
         "@types/mime": "*"
       }
     },
+    "@types/socket.io": {
+      "version": "1.4.38",
+      "resolved": "https://registry.npmjs.org/@types/socket.io/-/socket.io-1.4.38.tgz",
+      "integrity": "sha512-+f49CywK6w2RNDzcug7iUVZoC0262Wr6XrGg0yunW+wFBG8RXC8hiQm94HV1I3H0/8bEodGSjDOxd4i2yhFbwA==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "accepts": {
       "version": "1.3.5",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.5.tgz",

package.json

@@ -13,6 +13,7 @@
   "devDependencies": {
     "@types/es6-shim": "^0.31.37",
     "@types/express": "^4.16.0",
+    "@types/socket.io": "^1.4.38",
     "typescript": "^3.0.3"
   },
   "dependencies": {