Adjust board lists header text color

Adjusts regression fixed by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18786/. We were not returning the label text color correctly on the backend.

app/models/list.rb

@@ -31,7 +31,8 @@ class List < ActiveRecord::Base
       if options.key?(:label)
         json[:label] = label.as_json(
           project: board.project,
-          only: [:id, :title, :description, :color]
+          only: [:id, :title, :description, :color],
+          methods: [:text_color]
         )
       end
     end

app/views/shared/boards/components/_board.html.haml

@@ -15,7 +15,7 @@
           ":title" => '(list.label ? list.label.description : "")',
           data: { container: "body", placement: "bottom" },
           class: "label color-label title board-title-text",
-          ":style" => "{ backgroundColor: (list.label && list.label.color ? list.label.color : null), color: (list.label && list.label.text_color ? list.label.text_color : \"#2e2e2e\") }" }
+          ":style" => "{ backgroundColor: (list.label && list.label.color ? list.label.color : null), color: (list.label && list.label.textColor ? list.label.textColor : \"#2e2e2e\") }" }
           {{ list.title }}
 
         - if can?(current_user, :admin_list, current_board_parent)

spec/fixtures/api/schemas/list.json

@@ -17,6 +17,7 @@
       "required": [
         "id",
         "color",
+        "text_color",
         "description",
         "title",
         "priority"
@@ -29,6 +30,7 @@
         },
         "description": { "type": ["string", "null"] },
         "title": { "type": "string" },
+        "title": { "text_color": "string" },
         "priority": { "type": ["integer", "null"] }
       }
     },