fix #58: inverted creation of rfq and bids

The module purchase_requisition_auto_rfq_bid_selection is just a bridge:
it should not change the functionality of bids and rfqs:

- an open call for bids should have bids
- a restricted call for bids should have rfqs

Installing the bridge module the two get inverted. This fixes it.

The yaml test was inverted as well: it is flipped, too.
Merge pull request #59 from lepistone/fix-rfq-bid-inverted

fix inverted creation of rfq and bids