[fix] Updated build badge

@ghislaineguerin this is the final PR for updating this project to use Circle CI.

Unlike with the Jenkins builds, all projects branches is now staged, not just PRs. Staging is still available here: http://192.254.220.35/~rvi/style-guide-staging/. 

The only feature that couldn't be implemented in this build is the trigger from Component projects to update the style-guide. This feature will have to be implemented in the components' builds themselves- I will work on doing so with the angular-dotdotdot project as an example.

Let me know if have any questions or concerns re: the above. Please review. Thanks.