Upgrade guava to 23.6-jre

Change-Id: Ie386b3d42194041503dd2d79089cce601c7e0d48

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 3659076..21bfa56 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -28,8 +28,8 @@
 
 maven_jar(
     name = "guava",
-    artifact = "com.google.guava:guava:23.0",
-    sha1 = "c947004bb13d18182be60077ade044099e4f26f1",
+    artifact = "com.google.guava:guava:23.6-jre",
+    sha1 = "c0b638df79e7b2e1ed98f8d68ac62538a715ab1d",
 )
 
 maven_jar(