Updating data

[scourgemancer]

Adds code to periodically update the data, defaulting to updating at the beginning of every day.

[scourgemancer]

I'm not sure why the tests are failing. I don't believe that I modified the behaviors of any of the functions they called but it might be because of the new header in the tair.gaf file, though I find it hard to read where it would be getting called from.

[nicholastmosher]

    expect(jest.fn()).toHaveBeenCalledTimes(expected)
    Expected number of calls: 1
    Received number of calls: 0
      23 |     let foobar = jest.fn();
      24 |     startPeriodicallyCalling(foobar, 200, new Date(), 300);
    > 25 |     setTimeout(() => expect(foobar).toHaveBeenCalledTimes(1), 500);
         |                                     ^
      26 |   });
      27 | });
      28 |
      at src/utils/__tests__/test_data_fetcher.ts:25:37