[Review] Request from 'KalabiYau' @ 'SUSE/connect/review_140410_refactor_current_code'

Please review the following changes:
  * 1fa9a61 remove linux-utils as we dont rely on them anymore
  * f772610 Refactor credentials class
  * 3795d1f Bump version to 13
  * 455cb14 Cleanup logger
  * 32898e8 Remove uuid part - as generation of login is on server
  * 13f7716 Drop trailing empty line
  * 8576204 Use included class
  * c204b5a Cutoff uuid
  * 2bf6e95 Move authority of credentials to respective class
  * c7cdb1d Refactor credentials spec
  * fd24fa5 Move fixtures_dir into appropriate helper
  * d820583 Enforce single quotes in credentials spec