Upgrade joda-time to 2.9.9

Change-Id: Idf3d1acab7121fb6c0ce5b538ad99eddb8636980
diff --git a/WORKSPACE b/WORKSPACE
index 125c61f..d22ec4d 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -34,8 +34,8 @@
 
 maven_jar(
     name = "joda_time",
-    artifact = "joda-time:joda-time:2.9.8",
-    sha1 = "03986e1763e5df02ad7fc040ecb555193a8436bb",
+    artifact = "joda-time:joda-time:2.9.9",
+    sha1 = "f7b520c458572890807d143670c9b24f4de90897",
 )
 
 maven_jar(