Merge branch 'rs-repository-size-format' into 'master'

Use `number_to_human_size` helper to show repository size

This will intelligently format large repository sizes in GBs (or,
shudder, TBs).

Also, removes `rescue` clause from `repository_size` helper.
The repository size has since become calculated (and cached)
more intelligently, and this should no longer be necessary.

See merge request !4047

app/helpers/projects_helper.rb

@@ -200,12 +200,8 @@ module ProjectsHelper
   end
 
   def repository_size(project = @project)
-    "#{project.repository_size} MB"
-  rescue
-    # In order to prevent 500 error
-    # when application cannot allocate memory
-    # to calculate repo size - just show 'Unknown'
-    'unknown'
+    size_in_bytes = project.repository_size * 1.megabyte
+    number_to_human_size(size_in_bytes, delimiter: ',', precision: 2)
   end
 
   def default_url_to_repo(project = @project)