* Add Rakefile for easy install dotfiles
* Add tasks 'symlink' & 'uninstall'
   * it's a testing stage, but File.symlink behave just as one thought
* create tasks 'install' & 'symlink' & 'uninstall'
* Add re_install? method
   * print question on STDOUT to user wheather dotfiles install in your environments
* Add 'hoge' task
   * it will be removed
* create 'destination_path' method for unifying symbolic destination path
* Adapt destination_path method correspond to symbolic destination path
* All rename dotfiles or directory to file or directory name without 'dot'
   * ex) .emacs.d → emacs.d
   * Because it should not create symlink '.git' directory
* Deprecate 'dirs' method
   * It is unnecessary for any tasks
* Add blacklist_filename
   * The case that rake tasks should not want to target the files add to blacklist
* finish to create the 'backup' task
   * it have idempotency
* modify any descriptions on tasks
* create 'install' task and modify descriptions
* Modify 'symlink' task because it ask whether backup a target file for each that
* It is unnecessary for test to delete a 'hoge' file.