Update release-download.md (#2160)

Author: qiuxin2012

docs/docs/release-download.md

@@ -19,6 +19,15 @@ Here are the folders for nightly build packages. The packages are built from lat
 | Spark 2.1.1   | [download](https://oss.sonatype.org/content/groups/public/com/intel/analytics/bigdl/dist-spark-2.1.1-scala-2.11.8-linux64/0.4.0-SNAPSHOT/) |
 | Spark 2.2.0   | [download](https://oss.sonatype.org/content/groups/public/com/intel/analytics/bigdl/dist-spark-2.2.0-scala-2.11.8-linux64/0.4.0-SNAPSHOT/) |
 
+--- 
+
+## **Release 0.4.0**
+|               | Download Link (for Linux x64, Mac and Win64) |
+| ------------- | --------- |
+| Spark 1.5.2   | [download](https://s3-ap-southeast-1.amazonaws.com/bigdl-download/dist-spark-1.5.2-scala-2.10.5-all-0.4.0-dist.zip) |
+| Spark 1.6.2   | [download](https://s3-ap-southeast-1.amazonaws.com/bigdl-download/dist-spark-1.6.2-scala-2.10.5-all-0.4.0-dist.zip) |
+| Spark 2.1.1   | [download](https://s3-ap-southeast-1.amazonaws.com/bigdl-download/dist-spark-2.1.1-scala-2.11.8-all-0.4.0-dist.zip) |
+| Spark 2.2.0   | [download](https://s3-ap-southeast-1.amazonaws.com/bigdl-download/dist-spark-2.2.0-scala-2.11.8-all-0.4.0-dist.zip) |
 
 ---