Extend the API to include more repository properties (#33)

Adds description, stars_count, forks_count, watchers_count and
open_issues_count.

repo.go

@@ -23,11 +23,16 @@ type Repository struct {
 	ID          int64      `json:"id"`
 	Owner       *User      `json:"owner"`
 	FullName    string     `json:"full_name"`
+	Description string     `json:"description"`
 	Private     bool       `json:"private"`
 	Fork        bool       `json:"fork"`
 	HtmlUrl     string     `json:"html_url"`
 	CloneUrl    string     `json:"clone_url"`
 	SshUrl      string     `json:"ssh_url"`
+	Stars       int        `json:"stars_count"`
+	Forks       int        `json:"forks_count"`
+	Watchers    int        `json:"watchers_count"`
+	OpenIssues  int        `json:"open_issues_count"`
 	Permissions Permission `json:"permissions"`
 }