Verify your site(s) with Google Webmaster Tools

You can load simple synthetic files in nginx just by returning a value.

Drop this snippet into the server block in your host configs.

Even better, make an include for all your virtual hosts and put this in there!

# Google Webmaster tools Verification file
# You can get your verification file in the console when you add or verify a site
# https://www.google.com/webmasters/tools/home?hl=en&authuser=0
location = /google123456RANDOMNUMBER.html {
    add_header Content-Type text/html;
    return 200 'google-site-verification: google123456RANDOMNUMBER.html';
}