Merge branch 'hotfix/use-command-classes'
Use command classes (branching test)
Remove spec_list.txt
Move spec/lib/contest/driver/ => spec/contest_driver/
Move spec/bin/ => spec/command/
Support Command.new(args, custom_input_stream)
Use terminal.ask()
Remove bin_exec() from spec_helper
Use command classes (git contest config)
Merge branch 'hotfix/use-command-classes' into develop