Retry when suggested topic has no papers.

[eban12]

If Arxiv returns no papers for the randomly picked topic, it retries for maximum of 10 times. The maxRetries prevents the app form going into an infinite loop incases where all requests return empty list.

• Fixes Empty list when opening app #24

[eban12]

This is my attempt at fixing the issue #24. It might not be an elegant solution but it does solve the issue for the time being. A better solution might be to find a way to get a recommended or top papers endpoint from Arxiv api. Which would always be deterministic and guaranteed to return results. But I don't understand the Arxiv api enough to know if there is such an endpoint. Will try to look into it over the weekend or something. @dagmawibabi if you know if such an endpoint exists, let me know.

[dagmawibabi]

@eban12 great job. That's the exact kind of solution I would've had. 👏