update burndown_charts response

app/controllers/api/pm/sprint_issues_controller.rb

@@ -14,16 +14,13 @@ class Api::Pm::SprintIssuesController < Api::Pm::BaseController
     start_time = Date.parse params[:start_time]
     end_time = Date.parse params[:end_time]
     x = (end_time - start_time).to_i + 1 #计算间隔时间 加上最后一天
-    data = {}
+    data = []
     curren_issues =  @issues.group(:status_id,:due_date).count
     x.times do |time|
       e_time = start_time + time
       undone = curren_issues[[1,nil]].to_i + curren_issues[[1,e_time]].to_i + curren_issues[[2,e_time]].to_i + curren_issues[[3,e_time]].to_i
       completed = curren_issues[[4,e_time]].to_i + curren_issues[[5,e_time]].to_i
-      data[e_time] = {
-        undone: undone,
-        completed:completed
-      }
+      data << {time: e_time, undone: undone, completed:completed}
     end
     render_ok(data: data)
   end