Update SKP version to 13

R=rmistry@google.com

Author: borenet@google.com

Review URL: https://codereview.chromium.org/309753004
diff --git a/SKP_VERSION b/SKP_VERSION
index d00491f..ca7bf83 100644
--- a/SKP_VERSION
+++ b/SKP_VERSION
@@ -1 +1 @@
-1
+13
\ No newline at end of file