Fix some violation on rubocop
Add patterns_root variable to specify root directory of patterns
Refactoring: split logic to build of command and execute
Refactoring: Rename oss/os to operating_systems/operating_system
Refactoring: rename method from update_attributes to update_metadata to avoid unexpected override
Add default variables that is empty hash to avoid error when doesn't specify options
Refactoring: Change variable name to descriptive variable name
Fix argument error when parse a stdout of packer
Refactoring: Suppress warning that class length is exceeded by rubocop
Merge branch 'feature/add-patch' into develop
Merge branch 'feature/add-validate' into develop
Merge branch 'feature/os-candidate' into develop

Conflicts:
	spec/src/models/operating_system_spec.rb
	src/models/operating_system.rb
Merge branch 'feature/use-tenant-name-to-auth' into develop
Merge branch 'feature/create-system' into develop

Conflicts:
	db/seeds.rb
Merge branch 'fix/rubocop-violation' into develop
Restrict create_stack callback at first time only
Remove already unnecess aryarguments from call of CloudConductor::Client
Change check logic to notice a completion of stack
Add Serf::Client to request serf
Use Serf::Client to check running status of serf on frontend server