CORD-2084 Explicitly install cryptography package

Change-Id: I82838bf61bc4c66edbb86253b6d8e9ac6cb1202b
diff --git a/scripts/bootstrap_ansible.sh b/scripts/bootstrap_ansible.sh
index 3d089f3..5164095 100755
--- a/scripts/bootstrap_ansible.sh
+++ b/scripts/bootstrap_ansible.sh
@@ -23,6 +23,7 @@
 # apt-get update
 # apt-get install -y ansible
 apt-get -y install python-dev libffi-dev python-pip libssl-dev sshpass
+pip install cryptography==1.9
 pip install ansible==2.2.2.0
 mkdir -p /etc/ansible
 cp /maasdev/ansible/ansible.cfg /etc/ansible/ansible.cfg