Gemfile source, from :rubygems to https://rubygems.org

> The source :rubygems is deprecated because HTTP requests are insecure.
> Please change your source to 'https://rubygems.org' if possible, or 'http://rubygems.org' if not.
Merge pull request #4 from mariozaizar/master

Gemfile source, from :rubygems to https://rubygems.org