[COOK-2299] don't override attributes from parent class

These method overrides where stopping the `enabled` and `running`
attribute values from being read correctly by the Chef::Resource::Service
parent class.
level-up cookbook's test coverage

* add test coverage for [COOK-2299]
* add test coverage for resource default values initalized from node
attributes
* refactor tests to use `let` blocks and `subject`
* move rspec tests to spec directory
* split resource and provider specs into separate files for easier
navigation/maintenance
add test coverage for mirror simple service compat fix
DRY up Rakefile and add tasks that ship with `rspec` and `foodcritic`
Merge pull request #14 from opscode-cookbooks/COOK-2299

COOK-2299 - runit_service resource does not properly start a non-running service