message: Add: `bigNumber` util method mock
diff: @@ -4,6 +4,11 @@ export const objectToErrorString = jest.fn();
  export const getRandomValues = jest.fn(value => value);
  +export const bigNumber = jest.fn(value => ({
  + value,
  + toString: () => value,
  +}));
  +
  const utils = {
  warning,
  getRandomValues,
  