Auto ignore files declared on .gitignore

[fede-moya]

I faced an invalid json error while running the eslint plugin over a project. The root of the problem seems to be a memory allocation error. The CLI was analyzing files that I have under public/pacs where a lot of application-<hash>.js files live, this folder is ignored on .gitignore that's why I didn't face this issue when using the plugin on codeclimate.com. All this considered, it might be a good idea to auto ignore files declared on .gitignore