release v0.4.0

Author: mengxr

project/Build.scala

@@ -11,7 +11,7 @@ object Shading extends Build {
 
 
   lazy val commonSettings = Seq(
-    version := "0.3.0",
+    version := "0.4.0",
     name := "tensorframes",
     scalaVersion := sys.props.getOrElse("scala.version", "2.11.8"),
     organization := "databricks",