fix started_at check

app/serializers/analytics_build_entity.rb

@@ -13,7 +13,7 @@ class AnalyticsBuildEntity < Grape::Entity
   end
 
   expose :duration, as: :total_time do |build|
-    build_started?(build) ? distance_of_time_as_hash(build.duration.to_f) : {}
+    build.duration ? distance_of_time_as_hash(build.duration.to_f) : {}
   end
 
   expose :branch do
@@ -37,8 +37,4 @@ class AnalyticsBuildEntity < Grape::Entity
   def url_to(route, build, id = nil)
     public_send("#{route}_url", build.project.namespace, build.project, id || build)
   end
-
-  def build_started?(build)
-    build.duration && build[:started_at]
-  end
 end