Missing Price Data

Two possible reasons for this:

Default API key reached a usage cap.
The tests ran too quickly and price data couldn't be fetched before returning the test. You can manually slow down your tests with a dummy

To slow down unit tests, you can add a dummy test like this:

// Wait so the reporter has time to fetch and return prices from APIs.
// https://github.com/cgewecke/eth-gas-reporter/issues/254
describe("eth-gas-reporter workaround", () => {
  it("should kill time", (done) => {
    setTimeout(done, 2000);
  });
});