Merge pull request #1 from duckmole/master

Code quality improved by removing code duplication. Thanks @duckmole
Added guard for minitest.
Upgraded resque-scheduler version.
Removed ruby 1.9.2 build and added 2.0.0.
Configuration now keeps track of attributes when a block is given to the config method.
Moved specs to the jobz subdirectory so that Guard finds specs when updating lib.