Allow users to provide his own configuration

[JuanMaRuiz]

I think it would be great to allow users to provide his own file with his desired rules. If I'm not wrong this tool will use 'jquery' style by default: if there are no defined options, if style options is undefined or style is setted as 'jquery'. If options.style is angular it will work fine and will use the defaults configuration object. It will fail otherwise.

It would be great if you could have your own .commitplease.config.js file to configure your own rules.

What do you think @jzaefferer, make it sense for you?

Best regards.

Good job by the way.