Update Mongodb client to 2.2.4 (#2329)

* chore(package): update mongodb to version 2.2.4

https://greenkeeper.io/

* fix for mongo 2.2.4

* Delete schema promise on error...

- Just because this way we can let the adapter an opportunity to yield a new error....
OR A SUCCESS

* Fixes test

* Restore fix

spec/index.spec.js

@@ -65,7 +65,7 @@ describe('server', () => {
         expect(response.statusCode).toEqual(500);
         expect(body.code).toEqual(1);
         expect(body.message).toEqual('Internal server error.');
-        done();
+        reconfigureServer().then(done, done);
       });
     });
   });