Merge pull request #22 from kuaukutsu/feature/di_refactoring

di refactoring

Merge pull request #20 from kuaukutsu/feature/tests

tests refactoring

Merge pull request #19 from kuaukutsu/feature/state_step_data

state modify

Merge pull request #18 from kuaukutsu/feature/step_refactoring

step state model

Merge pull request #16 from kuaukutsu/feature/queue_refactoring

queue refactoring

Merge pull request #15 from kuaukutsu/feature/step_factory_refactoring

step factory refactoring

Merge pull request #14 from kuaukutsu/feature/step_factory

step factory refactoring

Merge pull request #12 from kuaukutsu/feature/naming_refactoring

naming refactoring

Merge pull request #11 from kuaukutsu/feature/callback_refactoring

callback refactoring

Merge pull request #10 from kuaukutsu/feature/runner_refactoring

runner refactoring