CONTRIBUTORS: add Bjorn Tipling <bjorn.tipling@gmail.com>

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5645085

AUTHORS

@@ -32,6 +32,7 @@ Arvindh Rajesh Tamilmani <art@a-30.net>
 Ben Olive <sionide21@gmail.com>
 Benny Siegert <bsiegert@gmail.com>
 Berengar Lehr <berengar.lehr@gmx.de>
+Bjorn Tipling <bjorn.tipling@gmail.com>
 Blake Mizerany <blake.mizerany@gmail.com>
 Bobby Powers <bobbypowers@gmail.com>
 Caine Tighe <arctanofyourface@gmail.com>

CONTRIBUTORS

@@ -64,6 +64,7 @@ Ben Olive <sionide21@gmail.com>
 Benny Siegert <bsiegert@gmail.com>
 Berengar Lehr <Berengar.Lehr@gmx.de>
 Bill Neubauer <wcn@golang.org> <wcn@google.com>
+Bjorn Tipling <bjorn.tipling@gmail.com>
 Blake Mizerany <blake.mizerany@gmail.com>
 Bobby Powers <bobbypowers@gmail.com>
 Brad Fitzpatrick <bradfitz@golang.org> <bradfitz@gmail.com>