Increase Juju bootstrap timeout to 15 minutes

Change-Id: I47308cfb1d2c8eb8ce428c0d5512e93a34974cbd
diff --git a/roles/juju-setup/templates/environments.yaml.j2 b/roles/juju-setup/templates/environments.yaml.j2
index 766812f..a98825a 100644
--- a/roles/juju-setup/templates/environments.yaml.j2
+++ b/roles/juju-setup/templates/environments.yaml.j2
@@ -5,4 +5,4 @@
         bootstrap-host: juju.cord.lab
         bootstrap-user: ubuntu
         default-series: {{ ansible_distribution_release }}
-
+        bootstrap-timeout: 900 # 15 minutes