We have moved our codebase and wiki to github. However the google code version still shows up really high on Google. Is there any way to do an auto redirect to github when people land on the Google code version?
I'm not sure how long this option has been available (it may be related to Google announcing they're shutting down Google Code), but you can now set a "project moved" flag which will provide all visitors to your Google Code project with a link to any other site, including GitHub.
Note: It doesn't appear that you can fully revert this setting, at least not at the time of my writing this, so be sure you really don't want to access anything from the Google Code project before setting it.