@1aurabrown => Place Bids

Adds the networking required to send the POST to submit a bid. Then sits at the confirmation page. Removes the `BiddingWebViewController.swift` 

Also:
* fixes #145 
* fixes #137 
* partial fix for #144
what does this look like on an ipad? Is katarina referring to using the OS number keyboard, or our custom keypad for the zipcode?