Handle the case where the CI service may not provide a status_img_path method.

app/views/projects/show.html.haml

@@ -64,8 +64,12 @@
 
           - @project.ci_services.each do |ci_service|
             - if ci_service.active? && ci_service.respond_to?(:builds_path)
-              = link_to ci_service.builds_path do
-                = image_tag ci_service.status_img_path, alt: "build status"
+              - if ci_service.respond_to?(:status_img_path)
+                = link_to ci_service.builds_path do
+                  = image_tag ci_service.status_img_path, alt: "build status"
+              - else
+                %span.light CI provided by
+                = link_to ci_service.title, ci_service.builds_path
 
   - if readme
     .tab-pane#tab-readme
@@ -76,3 +80,4 @@
             = readme.name
         .wiki
           = render_readme(readme)
+