Modified to use cfn_converter
Add specs to raise error when target stack does not exist
Destroy stacks in order that depends on type of pattern.
Fix rubocop violation
Change logic to destroy stacks from cfn adapter with stack name to Stack#destroy
Ensure destroy platform when some error occurred while destroying optional
Fix to valid status on AWS
Destroy all previous stacks and re-create when reset stacks
Merge branch 'feature/use-cfn-converter' into develop
Refactoring: System#destroy_stacks had changed to public method
Add Stack#exist? to check existence of stack
Use Stack#exist? to check existence of stack
Add DELETE_FAILED status to condition of destroyed stack
Merge branch 'feature/destroy-stacks-in-order' into develop
Update rspec version from rspec2 to rspec3
Remove already loaded gems by Bundler
Use expect syntax for mock instead of should syntax
Add spork to reduce load time for gems