API never refreshes auth token

When a Salesforce token expires, the `RestClient::apiCall` is never able to refresh it. The code looks like this:

    if (!$this->isInit()) {
      throw new RestException(NULL, $this->t('RestClient is not initialized.'));
    }
    if (!$this->authToken) {
      $this->authToken = $this->authManager->refreshToken();
    }

However, the problem is that if `$this->authToken` isn't set, the `isInit()` function returns FALSE. So the exception for "RestClient is not initialized' is thrown, and it never gets to the lines below to call `refreshToken`.

To make matters worse, the RestClient stores the `authToken` locally and does not expose any method for setting it or refreshing it. Using the Drush command as an example I can see how to refresh the token, but that doesn't actually update the token cached in the RestClient.

Any workaround would be appreciated, but the above logic also needs to be fixed so the apiCall is able to properly refresh tokens when they expire.

(Also note, we are not using the "pull" or "push" submodules, just using the RestClient, so we don't have any cron jobs to keep the API token active, nor do we want that. We want to properly refresh the token whenever it expires)