Use swagger-parser's namespace as type instead of defining our own.

types/swagger-express-middleware/index.d.ts

@@ -32,6 +32,9 @@ app.listen(8000, function () {
 
 declare module "swagger-express-middleware" {
     import { Application, Router, RequestHandler, Request, Response } from "express";
+    import * as parser from "swagger-parser";
+
+    type SwaggerParser = typeof parser.SwaggerParser;
 
     let s: s.SwaggerMiddlewareConstructor;
 
@@ -363,11 +366,6 @@ declare module "swagger-express-middleware" {
             externalDocs?: ExternalDocumentationObject
         }
 
-        export interface SwaggerParser {
-            $refs: any
-            schema: SwaggerObject
-        }
-
         type MimeTypes = string[]
 
         export interface InfoObject {