FIX: Cleanup migrations with timestamps in the future

A future-dated migration was accidently introduced by me in 45c399f0. This was removed in b9762afc, but other migrations had already been generated based on its incorrect date. This commit removes the offending data in the schema_migrations table, and corrects the version in the published_pages migration.

This commit also adds a check to db:migrate which raises an error when invalid migration timestamps are used.

lib/tasks/db.rake

@@ -187,6 +187,12 @@ end
 
 # we need to run seed_fu every time we run rake db:migrate
 task 'db:migrate' => ['load_config', 'environment', 'set_locale'] do |_, args|
+  migrations = ActiveRecord::Base.connection.migration_context.migrations
+  now_timestamp = Time.now.utc.strftime('%Y%m%d%H%M%S').to_i
+  epoch_timestamp = Time.at(0).utc.strftime('%Y%m%d%H%M%S').to_i
+
+  raise "Migration #{migrations.last.version} is timestamped in the future" if migrations.last.version > now_timestamp
+  raise "Migration #{migrations.first.version} is timestamped before the epoch" if migrations.first.version < epoch_timestamp
 
   ActiveRecord::Tasks::DatabaseTasks.migrate