Install python3.6-dev package in packer

Add python3.6-dev package which is needed by
pyCrypto.

Change-Id: Iaaa3fb8ca8d464e02af71ae50656861a5d104076
Issue-ID: CIMAN-108
Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
diff --git a/packer/provision/docker.sh b/packer/provision/docker.sh
index 325e328..125cbd4 100644
--- a/packer/provision/docker.sh
+++ b/packer/provision/docker.sh
@@ -35,7 +35,7 @@
     # Install Python3.6
     sudo add-apt-repository -y ppa:jonathonf/python-3.6
     sudo apt-get update
-    sudo apt-get install -y python3.6
+    sudo apt-get install -y python3.6 python3.6-dev
 
     # Install dependencies for robotframework and robotframework-sshlibrary
     apt install -y unzip sshuttle netcat libffi-dev libssl-dev