message: test(web-scripts): mock network for web-scripts audit
  the test fails frequently, as the connection to the auditing service seemingly gets throttled as we
  do so many in parallel. Instead, lets just mock it to avoid blocking PRs in annoying ways.
diff: @@ -20,6 +20,18 @@ import { auditTask } from '.';
  // @ts-ignore
  jest.spyOn(process, 'exit').mockImplementation(c => c);
  +jest.mock('cross-spawn-promise', () => jest.fn());
  +
  +const spawn: jest.Mock = require.requireMock('cross-spawn-promise');
  +
  +class AuditError extends Error {
  + public exitStatus: number;
  + constructor(message: string, exitStatus: number) {
  + super(message);
  + this.exitStatus = exitStatus;
  + }
  +}
  +
  /**
  * WARNING:
  * These tests have some issues with being potentially non-deterministic.
  @@ -54,6 +66,14 @@ describe('web-scripts audit', () => {
  async ({ violations, threshold, status }) => {
  const source = join(__dirname, '__fixtures__', violations.toString());
  + if (violations) {
  + spawn.mockRejectedValueOnce(
  + new AuditError('audit failure found', violations),
  + );
  + } else {
  + spawn.mockResolvedValueOnce(null);
  + }
  +
  await auditTask({
  name: 'audit',
  threshold,
  