Bump vcloud-core dep to 0.11.0 and release 0.6.0

Changes:
  - plaintext passwords are no longer permissible in FOG_RC
    See http://gds-operations.github.io/vcloud-tools/usage/
Merge pull request #54 from gds-operations/bump-core-0.11.0

Bump vcloud-core dep to 0.11.0 and release 0.6.0