新增：里程碑列表支持id查询

app/controllers/api/v1/issues/milestones_controller.rb

@@ -7,7 +7,7 @@ class Api::V1::Issues::MilestonesController < Api::V1::BaseController
   # 里程碑列表
   def index 
     @milestones = @project.versions
-    @milestones = @milestones.ransack(name_or_description_cont: params[:keyword]).result if params[:keyword].present?
+    @milestones = @milestones.ransack(id_eq: params[:keyword]).result.or(@milestones.ransack(name_or_description_cont: params[:keyword]).result) if params[:keyword].present?
     @closed_milestone_count = @milestones.closed.size 
     @opening_milestone_count = @milestones.opening.size
     @milestones = params[:category] == "closed" ? @milestones.closed : @milestones.opening