Removed unused Jodatime dependency

Change-Id: I69a443a1ce8e1813fd9ac547d3319c88301bf28e
diff --git a/build.sbt b/build.sbt
index a332f49..8e9e4c3 100644
--- a/build.sbt
+++ b/build.sbt
@@ -12,7 +12,6 @@
 
   // fixed versions for apache spark 2.1.1
   "org.json4s" %% "json4s-native" % "3.2.11",
-  "joda-time" % "joda-time" % "2.9.3",
 
   "com.github.scopt" %% "scopt" % "3.6.0",
   "org.scalactic" %% "scalactic" % "3.0.1" % "test",