Add possibility to persist all settings in config file

[jsirex]

According source code there are options and Config. I can populate settings for Config class. But it not used in runner.

I want to persist in my ~/.stove config file options like:

{
  "username": "admin",
  "key": "/home/sirex/.chef/admin.key",
  "endpoint": "https://supermarket.domain.local",
  "extended_metadata": true,
  "ssl_verify": false
  "no_git": true
}

3 last options are ignored now.

[dougireton]

See also #78