Merge branch 'add_waait' into 'master'

fix: add waait dependency

See merge request pubsweet/pubsweet!456

packages/server/package.json

@@ -48,6 +48,7 @@
     "pubsweet-sse": "^1.0.1",
     "subscriptions-transport-ws": "^0.9.12",
     "uuid": "^3.0.1",
+    "waait": "^1.0.2",
     "winston": "^2.2.0"
   },
   "devDependencies": {