message: cypress: log stdout/stderr when docker exec fails
  Otherwise you cannot debug anything with errors like:
  ```
  > Command failed: docker exec pg_isready -U postgres
  ```
  Now we include the stdout/err prior to logging this.
diff: @@ -61,9 +61,14 @@ export function dockerExec(args: {
  childProcess.execFile("docker", [
  "exec", args.containerId,
  ...args.params,
  - ], { encoding: 'utf8' }, err => {
  - if (err) reject(err);
  - else resolve();
  + ], { encoding: 'utf8' }, (err, stdout, stderr) => {
  + if (err) {
  + console.log(stdout);
  + console.log(stderr);
  + reject(err);
  + return;
  + }
  + resolve();
  });
  });
  }
  