Add a new link in third-party-projects.md
This pr added a new link in `third-party-projects.md`. I'm working on a Spark SQL server based on the PostgreSQL V3 protocol; it uses `Livy` for managing multiple `SparkContext` (See for details: https://github.com/maropu/spark-sql-server#execution-modes)
Author: Takeshi Yamamuro <yamamuro@apache.org>
Closes #23 from maropu/AddLink.
diff --git a/site/third-party-projects.md b/site/third-party-projects.md
index 96511c8..9bd6474 100644
--- a/site/third-party-projects.md
+++ b/site/third-party-projects.md
@@ -34,3 +34,5 @@
* [node-livy-client](https://www.npmjs.com/package/node-livy-client) - Livy client written in NodeJS
+* [spark-sql-server](https://github.com/maropu/spark-sql-server) - A Spark SQL server based on the PostgreSQL V3 protocol
+