rollback_exception

Fixed bug with env-configuration where hosts section containing deployment description.
Added delete-on-rollback option in general and env-deployment section

Bug with next case:
```
hosts:
  123.123.123.123:1234:
    tasks:
      on-deploy:
        - someTask1
        - someTask2
  123.123.123.124:1234:
    deployment:
      strategy: disabled
      user: someuser
      identity-file: /path/to/ssh/private/key
    tasks:
      on-deploy:
        - someBuiltIn/some-built-in-task
```