Added static method to AuctionInfo to calculate the previous bid from another known bid value.
Now possible to use multiple platforms simultaneously
Minor cleanup
Updated readme
Added missing leagueId to ItemData class

After todays maintenance, a property was missing on the ItemData class that made the deserialization fail.
Merge pull request #142 from mortenbock/patch-1

Added missing leagueId to ItemData class
Included leagueId in the JSON mock data
Merge branch 'futhome-not-static'