Add cookie parser dependency

services/real-time/package.json

@@ -10,6 +10,7 @@
   "dependencies": {
     "async": "^0.9.0",
     "connect-redis": "^2.1.0",
+    "cookie-parser": "^1.3.3",
     "express": "^4.10.1",
     "express-session": "^1.9.1",
     "logger-sharelatex": "git+https://github.com/sharelatex/logger-sharelatex.git#v1.0.0",