Enrich repository model

[rafaparadela]

We need to enrich the repository class in order to get an enhanced approximation to the value returned by Github (specially to include watchers, stars and forks):

{
  "id": 23613922,
  "name": "scala-exercises",
  "full_name": "scala-exercises/scala-exercises",
  "owner": {
    "login": "scala-exercises",
    "id": 17570897,
    "avatar_url": "https://avatars.githubusercontent.com/u/17570897?v=3",
    "gravatar_id": "",
    "url": "https://api.github.com/users/scala-exercises",
    "html_url": "https://github.com/scala-exercises",
    "followers_url": "https://api.github.com/users/scala-exercises/followers",
    "following_url": "https://api.github.com/users/scala-exercises/following{/other_user}",
    "gists_url": "https://api.github.com/users/scala-exercises/gists{/gist_id}",
    "starred_url": "https://api.github.com/users/scala-exercises/starred{/owner}{/repo}",
    "subscriptions_url": "https://api.github.com/users/scala-exercises/subscriptions",
    "organizations_url": "https://api.github.com/users/scala-exercises/orgs",
    "repos_url": "https://api.github.com/users/scala-exercises/repos",
    "events_url": "https://api.github.com/users/scala-exercises/events{/privacy}",
    "received_events_url": "https://api.github.com/users/scala-exercises/received_events",
    "type": "Organization",
    "site_admin": false
  },
  "private": false,
  "html_url": "https://github.com/scala-exercises/scala-exercises",
  "description": "The easy way to learn Scala.",
  "fork": false,
  "url": "https://api.github.com/repos/scala-exercises/scala-exercises",
  "forks_url": "https://api.github.com/repos/scala-exercises/scala-exercises/forks",
  "keys_url": "https://api.github.com/repos/scala-exercises/scala-exercises/keys{/key_id}",
  "collaborators_url": "https://api.github.com/repos/scala-exercises/scala-exercises/collaborators{/collaborator}",
  "teams_url": "https://api.github.com/repos/scala-exercises/scala-exercises/teams",
  "hooks_url": "https://api.github.com/repos/scala-exercises/scala-exercises/hooks",
  "issue_events_url": "https://api.github.com/repos/scala-exercises/scala-exercises/issues/events{/number}",
  "events_url": "https://api.github.com/repos/scala-exercises/scala-exercises/events",
  "assignees_url": "https://api.github.com/repos/scala-exercises/scala-exercises/assignees{/user}",
  "branches_url": "https://api.github.com/repos/scala-exercises/scala-exercises/branches{/branch}",
  "tags_url": "https://api.github.com/repos/scala-exercises/scala-exercises/tags",
  "blobs_url": "https://api.github.com/repos/scala-exercises/scala-exercises/git/blobs{/sha}",
  "git_tags_url": "https://api.github.com/repos/scala-exercises/scala-exercises/git/tags{/sha}",
  "git_refs_url": "https://api.github.com/repos/scala-exercises/scala-exercises/git/refs{/sha}",
  "trees_url": "https://api.github.com/repos/scala-exercises/scala-exercises/git/trees{/sha}",
  "statuses_url": "https://api.github.com/repos/scala-exercises/scala-exercises/statuses/{sha}",
  "languages_url": "https://api.github.com/repos/scala-exercises/scala-exercises/languages",
  "stargazers_url": "https://api.github.com/repos/scala-exercises/scala-exercises/stargazers",
  "contributors_url": "https://api.github.com/repos/scala-exercises/scala-exercises/contributors",
  "subscribers_url": "https://api.github.com/repos/scala-exercises/scala-exercises/subscribers",
  "subscription_url": "https://api.github.com/repos/scala-exercises/scala-exercises/subscription",
  "commits_url": "https://api.github.com/repos/scala-exercises/scala-exercises/commits{/sha}",
  "git_commits_url": "https://api.github.com/repos/scala-exercises/scala-exercises/git/commits{/sha}",
  "comments_url": "https://api.github.com/repos/scala-exercises/scala-exercises/comments{/number}",
  "issue_comment_url": "https://api.github.com/repos/scala-exercises/scala-exercises/issues/comments{/number}",
  "contents_url": "https://api.github.com/repos/scala-exercises/scala-exercises/contents/{+path}",
  "compare_url": "https://api.github.com/repos/scala-exercises/scala-exercises/compare/{base}...{head}",
  "merges_url": "https://api.github.com/repos/scala-exercises/scala-exercises/merges",
  "archive_url": "https://api.github.com/repos/scala-exercises/scala-exercises/{archive_format}{/ref}",
  "downloads_url": "https://api.github.com/repos/scala-exercises/scala-exercises/downloads",
  "issues_url": "https://api.github.com/repos/scala-exercises/scala-exercises/issues{/number}",
  "pulls_url": "https://api.github.com/repos/scala-exercises/scala-exercises/pulls{/number}",
  "milestones_url": "https://api.github.com/repos/scala-exercises/scala-exercises/milestones{/number}",
  "notifications_url": "https://api.github.com/repos/scala-exercises/scala-exercises/notifications{?since,all,participating}",
  "labels_url": "https://api.github.com/repos/scala-exercises/scala-exercises/labels{/name}",
  "releases_url": "https://api.github.com/repos/scala-exercises/scala-exercises/releases{/id}",
  "deployments_url": "https://api.github.com/repos/scala-exercises/scala-exercises/deployments",
  "created_at": "2014-09-03T09:14:41Z",
  "updated_at": "2016-06-19T20:24:00Z",
  "pushed_at": "2016-06-20T14:12:11Z",
  "git_url": "git://github.com/scala-exercises/scala-exercises.git",
  "ssh_url": "[email protected]:scala-exercises/scala-exercises.git",
  "clone_url": "https://github.com/scala-exercises/scala-exercises.git",
  "svn_url": "https://github.com/scala-exercises/scala-exercises",
  "homepage": "https://scala-exercises.org",
  "size": 10585,
  "stargazers_count": 428,
  "watchers_count": 428,
  "language": "Scala",
  "has_issues": true,
  "has_downloads": true,
  "has_wiki": false,
  "has_pages": true,
  "forks_count": 193,
  "mirror_url": null,
  "open_issues_count": 27,
  "forks": 193,
  "open_issues": 27,
  "watchers": 428,
  "default_branch": "master",
  "organization": {
    "login": "scala-exercises",
    "id": 17570897,
    "avatar_url": "https://avatars.githubusercontent.com/u/17570897?v=3",
    "gravatar_id": "",
    "url": "https://api.github.com/users/scala-exercises",
    "html_url": "https://github.com/scala-exercises",
    "followers_url": "https://api.github.com/users/scala-exercises/followers",
    "following_url": "https://api.github.com/users/scala-exercises/following{/other_user}",
    "gists_url": "https://api.github.com/users/scala-exercises/gists{/gist_id}",
    "starred_url": "https://api.github.com/users/scala-exercises/starred{/owner}{/repo}",
    "subscriptions_url": "https://api.github.com/users/scala-exercises/subscriptions",
    "organizations_url": "https://api.github.com/users/scala-exercises/orgs",
    "repos_url": "https://api.github.com/users/scala-exercises/repos",
    "events_url": "https://api.github.com/users/scala-exercises/events{/privacy}",
    "received_events_url": "https://api.github.com/users/scala-exercises/received_events",
    "type": "Organization",
    "site_admin": false
  },
  "network_count": 193,
  "subscribers_count": 54
}