pools: remove pool element destroy action.

This endpoint was for removing a single post from a pool. This wasn't
used anywhere within Danbooru.

app/controllers/pool_elements_controller.rb

@@ -12,11 +12,4 @@ class PoolElementsController < ApplicationController
       @error = "That pool does not exist"
     end
   end
-
-  def destroy
-    @pool = Pool.find(params[:pool_id])
-    @post = Post.find(params[:post_id])
-    @pool.remove!(@post)
-    respond_with(@pool, :location => post_path(@post))
-  end
 end

config/routes.rb

@@ -182,7 +182,7 @@ Rails.application.routes.draw do
     end
     resource :order, :only => [:edit], :controller => "pool_orders"
   end
-  resource :pool_element, :only => [:create, :destroy]
+  resource :pool_element, :only => [:create]
   resources :pool_versions, :only => [:index] do
     member do
       get :diff

test/functional/pool_elements_controller_test.rb

@@ -31,27 +31,5 @@ class PoolElementsControllerTest < ActionDispatch::IntegrationTest
         assert_equal([@post.id], @pool.post_ids)
       end
     end
-
-    context "destroy action" do
-      setup do
-        as_user { @pool.add!(@post) }
-      end
-
-      should "remove a post from a pool" do
-        delete_auth pool_element_path, @user, params: {:pool_id => @pool.id, :post_id => @post.id, :format => "json"}
-        @pool.reload
-        assert_equal([], @pool.post_ids)
-      end
-
-      should "do nothing if the post is not a member of the pool" do
-        @pool.reload
-        as_user do
-          @pool.remove!(@post)
-        end
-        delete_auth pool_element_path, @user, params: {:pool_id => @pool.id, :post_id => @post.id, :format => "json"}
-        @pool.reload
-        assert_equal([], @pool.post_ids)
-      end
-    end
   end
 end