Upgrade truth to version 0.39

Change-Id: I62f87f1b012728efa7f01cd34fd54c180bcd5876
diff --git a/WORKSPACE b/WORKSPACE
index 2ba1e23..c29dcac 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -104,8 +104,8 @@
 
 maven_jar(
     name = "truth",
-    artifact = "com.google.truth:truth:0.36",
-    sha1 = "7485219d2c1d341097a19382c02bde07e69ff5d2",
+    artifact = "com.google.truth:truth:0.39",
+    sha1 = "bd1bf5706ff34eb7ff80fef8b0c4320f112ef899",
 )
 
 maven_jar(