Google says URL restricted by robots.txt

Why does google webmaster tools keep saying URLS are restricted by my robots.txt?
I do not have a robots.txt file in the home directory.
I have unclicked discourage search engines.
I use this google xml sitemaps plugin and ask that the home page be included in the virtual robots.txt
When I go my site’s robots.txt it shows:

User-agent: *
Disallow: /wp-admin/
Disallow: /wp-includes/

Sitemap: http://ravenwoodtennis.com/sitemap.xml.gz

This doesn’t seem to be blocking the home page, etc.

PLUGIN RELATED: should I be changing the sitemap name to the sitemap_index.xml in the webmaster tools? If so, it’s generating a 404 error. 🙁

https://wordpress.org/plugins/google-sitemap-generator/