Rollback Versions Save

• Ability to roll back to a specific version, thanks @rev112
• Bye Ansible 1.8, unified with deploy

Fix rollback in BSD distros, thanks for reporting @ratbag98

Internal changes

• Symlinks are now relative instead of absolute

• Added registration of ansistrano_release_path variable in rollback setup so that hooks can be reused between deploy and rollback. Check #8 by @magi2c

• Prior to this tag, before-symlink.yml hooks would not have access to the ansistrano variable as they were created inside symlink.yml. We added a setup step so that this was not problem. (Reported at https://github.com/ansistrano/rollback/issues/6)

New features

• Added possibility to not delete rolled back release for later inspection in the servers