The server_name variable isn't used since we removed the Apache task in
commit 012d5297e, db_server and config_files aren't used since we
removed the capistrano templates in that same commit, and full_app_name
isn't used since commit 94a7e13dc.
The following parameters have been added to deploy-secrets.yml:
* **use_rvm**: yes/no
* **ruby_version**: Ruby version for rvm. Defaults to 2.3.2
* **repository**: Git repository. Defaults to the oficial repository
* **branch**: Branch to deploy. Defaults to master
* **rails_env**: Defaults to the stage.
Fixed migrations that required admin rights. Now first check if the postgress extensions are available. If so finish without doing nothin.
Added support for passenger.
