tests: drop PostSets::Pool tests.

We no longer use this class for pool show pages. Only used by
inheritance by PostSets::FavoriteGroup.

test/unit/post_sets/pool_test.rb

@@ -1,62 +0,0 @@
-require 'test_helper'
-
-module PostSets
-  class PoolTest < ActiveSupport::TestCase
-    context "In all cases" do
-      setup do
-        @user = FactoryBot.create(:user)
-        CurrentUser.user = @user
-        CurrentUser.ip_addr = "127.0.0.1"
-
-        mock_pool_archive_service!
-        start_pool_archive_transaction
-
-        @post_1 = FactoryBot.create(:post)
-        @post_2 = FactoryBot.create(:post)
-        @post_3 = FactoryBot.create(:post)
-        @pool = FactoryBot.create(:pool)
-        @pool.add!(@post_2)
-        @pool.add!(@post_1)
-        @pool.add!(@post_3)
-      end
-
-      teardown do
-        rollback_pool_archive_transaction
-        CurrentUser.user = nil
-        CurrentUser.ip_addr = nil
-      end
-
-      context "a post pool set for page 2" do
-        setup do
-          @set = PostSets::Pool.new(@pool, 2)
-          @set.stubs(:limit).returns(1)
-        end
-
-        should "return the second element" do
-          assert_equal(1, @set.posts.size)
-          assert_equal(@post_1.id, @set.posts.first.id)
-        end
-
-        should "know the total number of pages" do
-          assert_equal(3, @set.total_pages)
-        end
-
-        should "know the current page" do
-          assert_equal(2, @set.current_page)
-        end
-      end
-
-      context "a post pool set with no page specified" do
-        setup do
-          @set = PostSets::Pool.new(@pool)
-          @set.stubs(:limit).returns(1)
-        end
-
-        should "return the first element" do
-          assert_equal(1, @set.posts.size)
-          assert_equal(@post_2.id, @set.posts.first.id)
-        end
-      end
-    end
-  end
-end