So I did all these things:
1. put this line of code in my header.php of my child theme:
<link rel="author" href="https://plus.google.com/u/0/?tab=wX#105742734776185198421/posts" />
(as you can see, my Google+ address is:
https://plus.google.com/u/0/?tab=wX#105742734776185198421/posts
2. added my site as a contributor in the Google+
3. made my Google+ +1s public
However, when I got to the Google Structured Data Testing Tool and run the site preview, I get:
Authorship rel=author Markup
Cannot verify that rel=author markup has established authorship for this webpage.
First rel=author link from webpage: https://plus.google.com/u/0/?tab=wX#105742734776185198421/posts
Link (direct or indirect) from website to Google+ profile: No
Can anyone see what I am doing wrong?