Move StemcellRakeMethods functionality into StemcellBuilder
Move StemcellRakeMethods code into StemcellBuilder
Refactor #build into private methods for clarity
Fix missing require
Add git-duet so commits have real users
add class to handle OperatingSystem
Remove unnecessary require

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Promote TrivialAccessors exception

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Introduce bosh-core gem

* To extract reusable code from bosh-dev into a production-worthy location
* bosh_common isn't a good candidate as it doesn't respect the loadpath
  i.e. require 'common' vs require 'bosh/core'
* Too many things depend on bosh_common to change it safely

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Move Shell into Bosh::Core so Bosh::Stemcell can eventually use it

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Promote AvoidPerlisms since $? and $CHILD_STATUS are not the same

Signed-off-by: Colin Humphreys <chumphreys@pivotallabs.com>
gem.rake assumes a version.rb, but gemspecs use BOSH_VERSION!

Signed-off-by: Colin Humphreys <chumphreys@pivotallabs.com>