[release-branch.go1.6] go1.6.4

Change-Id: I2deb44b5ba64e0838cf15f79aebc911ee38f6954
Reviewed-on: https://go-review.googlesource.com/33797
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

VERSION

diff --git a/VERSION b/VERSION
index 278d291..732f0934 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-go1.6.3
\ No newline at end of file
+go1.6.4
\ No newline at end of file