Also update version in description

Author: hadley

DESCRIPTION

@@ -2,7 +2,7 @@ Package: roxygen2
 Title: In-source documentation for R
 Description: A Doxygen-like in-source documentation system
     for Rd, collation, and NAMESPACE.
-Version: 3.0.0.99
+Version: 3.1.0
 License: GPL (>= 2)
 Authors@R: c(
     person("Hadley", "Wickham", email = "h.wickham@gmail.com",