[Review] Request from 'vlewin' @ 'SUSE/connect/review_140731_s390_support'

Please review the following changes:
  * 907974d add test for read_values parsing
  * cfacac1 add test for hostname
  * f1d2245 add read_values fixture (s390)
  * 60df5e8 fix rubocop warnings
  * 91b577b fix copy&paste issue
  * ca8d68e delegate hostname to SUSE::Connect::System
  * 509e77a mute rubocop
  * 40c08ef remove hwinfo module
  * 9106221 fix unit tests
  * 333e625 don't cache @arch
  * 1d9c7f6 replace debug with byebug
  * fa17464 call SUSE::Connect::HwInfo::Base.info and clean up moved methods
  * 9dcc58f require SUSE::Connect::HwInfo::Base
  * d55d949 introduce SUSE::Connect::HwInfo::S390 class
  * 33e5a35 introduce SUSE::Connect::HwInfo::X86 class
  * 9e2879d introduce SUSE::Connect::HwInfo::Base class
i think that arch and two methods below are really about system, because arch is characteristics  of system