fix link in contributing template (#337)

.github/CONTRIBUTING.md

@@ -1,5 +1,5 @@
 Ask questions at
 [StackOverflow](https://stackoverflow.com/questions/ask?tags=go+redis).
 
-[Open an issue](https://github.com/garyburd/redigo/issues/new) to discuss your
+[Open an issue](https://github.com/gomodule/redigo/issues/new) to discuss your
 plans before doing any work on Redigo.