550 drupal 7 does not import author name email

[lyndseypadget]

Fixes #550.

While the issue was written up for Drupal 7, I realized that the drupal7 and drupal8 importers share a common file. I believe this approach should work for Drupal 8 as well, and it's reasonable to assume that users would want author name and email supported in both versions.

As mentioned in the issue description, I could use some guidance on how to test this. Or, provide a build and I'll be the guinea pig! (For Drupal 7 at least.)