https://github.com/OmarElKhaldi/strawberryhunter/issues/3

- Adding a class that tests the backup server in the first scenario.
 The first scenario consists on adding a backupServer before launching the
 clients.
https://github.com/OmarElKhaldi/strawberryhunter/issues/3

- Adding the class that tests if the backup gets the sweets correctly from
  the primary
https://github.com/OmarElKhaldi/strawberryhunter/issues/3

- Adding functions that helps the backup server to extract the clients
  from the primary server.
- Testing the extraction of the clients from the server to the backup.