Use 'items()' for python compatibility

roles/etcd/templates/etcd.env.j2

@@ -28,6 +28,6 @@ ETCD_PEER_CERT_FILE={{ etcd_cert_dir }}/member-{{ inventory_hostname }}.pem
 ETCD_PEER_KEY_FILE={{ etcd_cert_dir }}/member-{{ inventory_hostname }}-key.pem
 ETCD_PEER_CLIENT_CERT_AUTH={{ etcd_peer_client_auth }}
 
-{% for key, value in etcd_extra_vars.iteritems() %}
+{% for key, value in etcd_extra_vars.items() %}
 {{ key }}={{ value }}
 {% endfor %}