新增：转账记录使用json builder以及贡献者新增贡献占比

app/models/concerns/watchable.rb

@@ -31,11 +31,9 @@ module Watchable
     following.size
   end
 
-  def contribution_perc
-    project_identifier = params[:project_identifier]
-    user_login = params[:id]
-    @project = Project.find_by_identifier(project_identifier)
-    @user = User.find_by_login(user_login)
+  def contribution_perc(project)
+    @project = project
+    @user = self
 
     def cal_perc(count_user, count_all)
       (count_user * 1.0 / (count_all + 0.000000001)).round(5)