Here is an article from Feb, but it looks like Wimby will be ramping up testing efforts more than other GSs. I doubt they will publicize the results though, similar to the French Open when 6/8 of the Quarter finalists tested positive and they couldn't take action or there would be no tournament.
http://www.sportsmole.co.uk/tennis/news/wimbledon-plans-further-drug-testing_71280.html
http://www.sportsmole.co.uk/tennis/news/wimbledon-plans-further-drug-testing_71280.html