Link branch name on build page.

app/views/projects/builds/show.html.haml

@@ -7,7 +7,7 @@
     %strong.monospace
       = link_to @build.commit.short_sha, ci_status_path(@build.commit)
     from
-    %code #{@build.ref}
+    = link_to @build.ref, namespace_project_commits_path(@project.namespace, @project, @build.ref)
   #up-build-trace
   - if @commit.matrix_for_ref?(@build.ref)