command classes moved to cli module
move requires
bugfix: autoload fail
move dump subcommand to tools module
use pry on runtime
use RUN_AS environment as log filename
refactory for functional step

* move Step to CmdStep and add FunctionStep
* use run_on(node) as a abstract method of all Steps
* source_accessor use update_source method to `do` update
* model Node execute method accept actual command
open Larrow::Runner module for classes
bug fixed: add title to FunctionStep
bug fixed: return configuration of methods