fix(package): update swagger-express-middleware to version 4.0.0

Closes #244

Author: greenkeeper[bot]

package.json

@@ -80,7 +80,7 @@
     "rxjs": "^6.5.3",
     "scrape-it": "^5.2.0",
     "source-map-support": "^0.5.16",
-    "swagger-express-middleware": "^2.0.4",
+    "swagger-express-middleware": "^4.0.0",
     "swagger-ui-express": "^4.1.2",
     "yamljs": "^0.3.0"
   },