Update .gitignore with VSCode artifacts

Added .vscode/ directory to .gitignore.

Change-Id: Ifc4083787b132f6455023c9b2f52a82a1b8626a7
Reviewed-on: http://gerrit.cloudera.org:8080/15061
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
diff --git a/.gitignore b/.gitignore
index b208652..d98de44 100644
--- a/.gitignore
+++ b/.gitignore
@@ -98,6 +98,9 @@
 eclipse-classes/
 .pydevproject
 
+# Visual Studio Code artifacts
+.vscode/
+
 # Debugging
 ad-hoc.test
 nohup.out