Update deployment code to improve debugging

Add some logging for deploy celery task and chef_installer
environment update.

- Fix a bug in chef databag updating logic (missing .tmpl file
  extension in the file path)
- Temporarily comment out databag update due to template mis-config.
- Rename the OpenStack Icehouse flavor config values
  (to fix the mismatch of template names)

Change-Id: I856f7896156158f1c4f5a4cd654c8c93213a2879