Upgrade express

.gitignore

@@ -7,4 +7,6 @@ test/e2e/reports
 selenium-debug.log
 .idea/
 package-lock.json
-ptinvites.json
+ptinvites.json
+settings.json
+.tmp

package.json

@@ -14,6 +14,7 @@
     "args-parser": "^1.1.0",
     "body-parser": "^1.18.2",
     "cors": "^2.8.3",
+    "express": "^4.16.3",
     "jsonfile": "^4.0.0",
     "socket.io": "^2.0.3",
     "videojs-contrib-hls": "^5.5.2",
@@ -35,7 +36,6 @@
     "copy-webpack-plugin": "^4.0.1",
     "css-loader": "^0.28.0",
     "eventsource-polyfill": "^0.9.6",
-    "express": "^4.14.1",
     "extract-text-webpack-plugin": "^2.0.0",
     "file-loader": "^0.11.1",
     "friendly-errors-webpack-plugin": "^1.1.3",