chore(deps): update dependency express to v4.21.0

Author: renovate[bot]

packages/o-express-middleware/package.json

@@ -49,12 +49,12 @@
   },
   "devDependencies": {
     "@types/axios": "0.14.0",
-    "@types/express": "4.16.0",
+    "@types/express": "4.17.21",
     "@types/jest": "23.3.2",
     "@types/node": "10.5.2",
     "@types/winston": "2.3.9",
     "codecov": "3.0.4",
-    "express": "4.16.3",
+    "express": "4.21.0",
     "jest": "23.4.0",
     "jest-extended": "0.7.2",
     "ts-jest": "24.0.0",