Merge branch 'issue-2306-repo-size-display' into 'master'

Add size information back to project summary screen.

![gitlab-with-size](https://gitlab.com/nneul/gitlab-ce/uploads/84d15169aa7ee4e966465a71ca383f24/gitlab-with-size.png)

See merge request !1178

app/views/projects/show.html.haml

@@ -23,6 +23,10 @@
       = link_to namespace_project_tags_path(@project.namespace, @project) do
         = pluralize(number_with_delimiter(@repository.tag_names.count), 'tag')
 
+    %li
+      = link_to namespace_project_path(@project.namespace, @project) do
+        = repository_size
+
     - if !prefer_readme? && @repository.readme
       %li
         = link_to 'Readme', readme_path(@project)