remove old migration spec, because it tries to downgrade later migrations

spec/migrations/remove_duplicate_and_empty_pods_spec.rb

@@ -1,64 +0,0 @@
-
-require "spec_helper"
-require Rails.root.join("db/migrate/20150828132451_remove_duplicate_and_empty_pods.rb")
-
-describe RemoveDuplicateAndEmptyPods do
-  self.use_transactional_fixtures = false
-
-  before do
-    @previous_migration = 20_150_731_123_114
-    @my_migration = 20_150_828_132_451
-    Pod.delete_all
-  end
-
-  after :all do
-    migrate_to(nil) # up
-    Pod.delete_all # cleanup manually, transactions are disabled
-  end
-
-  def migrate_to(version)
-    ActiveRecord::Migrator.migrate(Rails.root.join("db", "migrate"), version)
-  end
-
-  describe "#up" do
-    before do
-      migrate_to(@previous_migration)
-
-      FactoryGirl.create(:pod, host: nil)
-      FactoryGirl.create(:pod, host: "")
-      4.times { FactoryGirl.create(:pod, host: "aaa.aa") }
-    end
-
-    it "removes duplicates" do
-      expect(Pod.where(host: "aaa.aa").count).to eql(4)
-      migrate_to(@my_migration)
-      expect(Pod.where(host: "aaa.aa").count).to eql(1)
-    end
-
-    it "removes empty hostnames" do
-      expect(Pod.where(host: [nil, ""]).count).to eql(2)
-      migrate_to(@my_migration)
-      expect(Pod.where(host: [nil, ""]).count).to eql(0)
-    end
-
-    it "adds an index on the host column" do
-      expect {
-        migrate_to(@my_migration)
-        Pod.reset_column_information
-      }.to change { Pod.connection.indexes(Pod.table_name).count }.by(1)
-    end
-  end
-
-  describe "#down" do
-    before do
-      migrate_to(@my_migration)
-    end
-
-    it "removes the index on the host column" do
-      expect {
-        migrate_to(@previous_migration)
-        Pod.reset_column_information
-      }.to change { Pod.connection.indexes(Pod.table_name).count }.by(-1)
-    end
-  end
-end