Install Python3.6 for Ubuntu basebuild images

Add Python3.6 version to be used by dcaegen2
project.

Change-Id: I7bd5f28958144cbf16e22c1328f5683ee30d737a
Issue-ID: CIMAN-108
Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
diff --git a/packer/provision/basebuild.sh b/packer/provision/basebuild.sh
index 261f75f..853afc7 100644
--- a/packer/provision/basebuild.sh
+++ b/packer/provision/basebuild.sh
@@ -53,6 +53,11 @@
 }
 
 ubuntu_systems() {
+    # Install python3.6
+    sudo add-apt-repository -y ppa:jonathonf/python-3.6
+    sudo apt-get update
+    sudo apt-get install -y python3.6
+
     # Install python dependencies
     apt-get install -y python-{dev,virtualenv,setuptools,pip}