List of project contributors

1. Get the list of contributors to the project from `http://api.github.com`
2. Display the results on a separate page `/contributors` with Github username, avatar, link to Github profile and contributions made to the project.

Tested with 
Cucumber: `features/display_project_contributors.feature`
Rspec:  `spec/requests/contributors_spec.rb` and `spec/views/contributors/show.html_spec.rb`

TODO? This is a simple presentation of project members that have made contributions to the Local Support project. Should we add more information about Agile Ventures with possibly a link to www.agileventures.org?