Source with missing county data should return 404

[Kilo59]

Trying to get county data for a source that doesn't contain that level of detail should return a 404

https://coronavirus-tracker-api.herokuapp.com/v2/locations?source=jhu&province=North%20Carolina&county=Wake

{
  "latest": {
    "confirmed": 0,
    "deaths": 0,
    "recovered": 0
  },
  "locations": Array[0][
    
  ]
}

https://coronavirus-tracker-api.herokuapp.com/v2/locations?source=csbs&province=North%20Carolina&county=Wake

{
  "latest": {
    "confirmed": 73,
    "deaths": 0,
    "recovered": 0
  },
  "locations": Array[1][
    {
      "id": 678,
      "country": "US",
      "country_code": "US",
      "county": "Wake",
      "province": "North Carolina",
      "last_updated": "2020-03-25T03:05:00Z",
      "coordinates": {
        "latitude": "35.79010846",
        "longitude": "-78.65039764"
      },
      "latest": {
        "confirmed": 73,
        "deaths": 0,
        "recovered": 0
      }
    }
  ]
}

If no one else addresses it first, I should be able to fix this tonight.

[ExpDev07]

Just at the end after filtering locations:

len(locations) == 0:
    # return 404 with descriptive message