Add PYPI packages to lxd image

Add a path to pre-installing packages from PYPI that are common
to reactive charms and VNF configuration charms for faster
deployment times.

Signed-off-by: Adam Israel <adam.israel@canonical.com>
diff --git a/jenkins/VCA/update-lxd-image.sh b/jenkins/VCA/update-lxd-image.sh
index 182a33c..07ba90b 100755
--- a/jenkins/VCA/update-lxd-image.sh
+++ b/jenkins/VCA/update-lxd-image.sh
@@ -21,6 +21,9 @@
 
 PACKAGES="$LAYER_BASIC $DOWNLOAD_PACKAGES"
 
+# Packages from pypi to pre-install
+PYPI="charms.reactive charmhelpers paramiko>=1.16.0,<1.17"
+
 function cache() {
     series=$1
     container=juju-${series}-base
@@ -35,6 +38,7 @@
     lxc exec $container -- apt-get update -y
     lxc exec $container -- apt-get upgrade -y
     lxc exec $container -- apt-get install -y $PACKAGES $2
+    lxc exec $container -- pip3 install --upgrade $PYPI
     lxc stop $container
 
     lxc image delete $alias || true