Rtbkit 634 http bidding interface example

Adds python implementation of a bid agent using http api.
That's not quite what I meant. The router has a series of filters which are used to determine which creativess of an agent are available for bidding on a given impression. This information is usually transmitted in the Bids structure but the HTTP protocol doesn't currently include it. This means that the creative you select could be rejected by the router (eg. its dimmensions don't match the allowed dimmensions on the impressions).