Bump up yangtools to 2.3 version

Change-Id: Ia56b3a3866760a58aa541604a20f23317fe94b4d
diff --git a/tools/dev/bin/patch-yang-libs b/tools/dev/bin/patch-yang-libs
index a44613d..edfc2f1 100755
--- a/tools/dev/bin/patch-yang-libs
+++ b/tools/dev/bin/patch-yang-libs
@@ -3,7 +3,7 @@
 # Patches lib/BUCK file to use locally built YANG tools.
 # -----------------------------------------------------------------------------
 
-BVER=2.3.0-b3
+BVER=2.3
 SVER=2.3-SNAPSHOT
 
 YANG_TOOLS_ROOT=${YANG_TOOLS_ROOT:-~/onos-yang-tools}