Update custom-victory-green.html

I took out a lot of `bgcolor` attributes from table and td elements. It's generally better to use CSS to style the backgrounds. In addition, you'll probably want to bring any styles you declare at the top inline (like I've done with the body tag styles).

I tend to use this: http://htmlemailboilerplate.com/ as a starting point when doing any kind of email templating, as it has some awesome stuff built into it.