Create a shim that hooks up wolpertinger with bridgestrap

We designed bridgestrap to help BridgeDB with testing bridges but it can also help us measure censorship. The idea is to deploy bridgestrap instances on VPSs and have them ask wolpertinger for bridges to test. This diagram shows the big picture.

We could build this functionality directly into bridgestrap but it would be cleaner to write a separate tool that relays information between wolpertinger and bridgestrap.