try to use yum instead of pip to install passlib

Former-commit-id: 22a0d30024a6dbe160706df666bb6a8030b15c40

ansible/deploy.yaml

@@ -93,7 +93,7 @@
         settings: "ippisite.{{ ansible_hostname }}_settings"
     # FIXME: this should obviously be removed before switching to prod. env.
     - name: install passlib for htpasswd in ansible
-      pip: name=passlib executable=pip3
+      yum: name=python-passlib state=installed
     - htpasswd:
         path: /etc/ippidb-80/passwdfile
         name: ippidb