Update how commits are found for a project (uses repos now)

Here are the routes:

         Prefix Verb   URI Pattern                                 Controller#Action
project_commits GET    /projects/:project_id/commits(.:format)     commits#index
 project_commit GET    /projects/:project_id/commits/:id(.:format) commits#show
  project_repos GET    /projects/:project_id/repos(.:format)       repos#index
                POST   /projects/:project_id/repos(.:format)       repos#create
   project_repo GET    /projects/:project_id/repos/:id(.:format)   repos#show
       projects GET    /projects(.:format)                         projects#index
                POST   /projects(.:format)                         projects#create
        project GET    /projects/:id(.:format)                     projects#show
   repo_commits POST   /repos/:repo_id/commits(.:format)           commits#create
          repos GET    /repos(.:format)                            repos#index
                POST   /repos(.:format)                            repos#create
       new_repo GET    /repos/new(.:format)                        repos#new
      edit_repo GET    /repos/:id/edit(.:format)                   repos#edit
           repo GET    /repos/:id(.:format)                        repos#show
                PATCH  /repos/:id(.:format)                        repos#update
                PUT    /repos/:id(.:format)                        repos#update
                DELETE /repos/:id(.:format)                        repos#destroy