Merge pull request #4 from ko1nksm/implement_2.0.0

Implement 2.0.0

Author: ko1nksm

Makefile

@@ -4,7 +4,7 @@ test:
 	shellspec
 
 check:
-	shellcheck getoptions.sh getoptions_help.sh sample/basic.sh sample/advanced.sh
+	shellcheck getoptions.sh getoptions_help.sh spec/getoptions_spec.sh spec/getoptions_help_spec.sh sample/basic.sh sample/advanced.sh sample/extension.sh
 
 testall:
 	shellspec -s sh