Moved doc folder creation in to seperate rake task.

- create new rake namepspace and task for
  setup:create_new_doc_folder_if_needed.
- moved folder creation in to new task.
- added setup:create_new_doc_folder_if_needed to default
  rake tasks.
Merge pull request #63 from Rudikza/fix_default_folder_creation

fix_default_folder_creation