relation batch_order doesn't quote table and column names

Thus if I'm using singular table names on postgres and querying against user it throws a syntax error because it's a reserved word (keyword). This showed up when trying to index on heroku with sunspot rails (solr).

The fix:

In batch_order in lib/active_record/relation/batches.rb change:

"#{@klass.table_name}.#{@klass.primary_key} ASC"

to:

"\"#{@klass.table_name}\".\"#{@klass.primary_key}\" ASC"