Update mongodb to the latest version 🚀 (#6348)

* fix(package): update mongodb to version 3.5.0

* chore(package): update lockfile package-lock.json

* Fix shutdown issues

Properly retrieves the number of connections

https://docs.mongodb.com/manual/reference/command/serverStatus/#connections

Bump to 3.5.1

* remove fit

Co-authored-by: Diamond Lewis <findlewis@gmail.com>

spec/ParseServer.spec.js

@@ -106,7 +106,7 @@ describe('Server Url Checks', () => {
     parseServerProcess.on('close', code => {
       expect(code).toEqual(1);
       expect(stdout).toBeUndefined();
-      expect(stderr).toContain('MongoNetworkError');
+      expect(stderr).toContain('MongoServerSelectionError');
       done();
     });
   });