Upgrade some deps (#3780)

* Upgrade TS

* Remove unused uglifyjs webpack plugin

* Upgrade some webpack stuff

package.json

@@ -150,18 +150,17 @@
     "require-dir": "^1.2.0",
     "sinon": "^7.3.1",
     "terser-webpack-plugin": "^1.2.3",
-    "ts-loader": "^6.0.4",
+    "ts-loader": "^6.1.1",
     "ts-mocha": "^6.0.0",
     "tslint": "^5.14.0",
     "tslint-config-prettier": "^1.18.0",
     "tslint-eslint-rules": "^5.4.0",
     "tslint-plugin-prettier": "^2.0.1",
-    "typescript": "^3.4.1",
-    "uglifyjs-webpack-plugin": "^2.1.2",
+    "typescript": "^3.6.3",
     "web-component-tester": "^6.9.2",
-    "webpack": "^4.29.6",
-    "webpack-cli": "^3.3.0",
-    "webpack-dev-server": "^3.2.1",
+    "webpack": "^4.40.2",
+    "webpack-cli": "^3.3.9",
+    "webpack-dev-server": "^3.8.1",
     "webpack-manifest-plugin": "^2.0.4",
     "workbox-webpack-plugin": "^4.1.1",
     "workerize-loader": "^1.1.0"