Extended the `RequestOptions` interface with `retryCodes` and `noRetryCodes` options, added the implementation for that in `index.js` by creating the function `_shouldRetryOnCode`, which has the hierarchy `retryCodes` > `noRetryCodes` > `DefaultHttpResponseRetryCodes`. Also fixed the failing unit tests by updating the imports (can be reverted if that was not needed, but in my case it was) and wrote new unit tests for the retry mechanism. Wrote the unit tests by adding the variable `retryCount` to `HttpClientResponse` to be able to track the amount of retries done. This is also very usefull for logging in production, as there is no current method for that.