Update express-ws, ts-loader and webpack

package.json

@@ -37,19 +37,19 @@
     "@types/ws": "^6.0.1",
     "chai": "3.5.0",
     "express": "^4.17.1",
-    "express-ws": "2.0.0-rc.1",
+    "express-ws": "^4.0.0",
     "glob": "^7.0.5",
     "jsdom": "^11.11.0",
     "mocha": "^6.1.4",
     "node-pty": "0.7.6",
     "puppeteer": "^1.15.0",
     "source-map-loader": "^0.2.4",
-    "ts-loader": "^4.5.0",
+    "ts-loader": "^6.0.4",
     "tslint": "^5.18.0",
     "tslint-consistent-codestyle": "^1.13.0",
     "typescript": "3.5",
     "utf8": "^3.0.0",
-    "webpack": "^4.17.1",
+    "webpack": "^4.35.3",
     "webpack-cli": "^3.1.0",
     "ws": "^7.0.0",
     "xterm-benchmark": "^0.1.3"