importing json card list

Dropped the [hearthstonejson](http://hearthstonejson.com/#documentation) json file in, and added a tool to parse it and run some tests on the numbers of spells/minions expected. This data is extracted directly from the gamefiles, so provides a good basis on comparing our implemented cards list to what's actually in the game. I'm going to add an ignored test to compare our implemented cards with what's in the file so we can track how far we are from full implementation. 

Eventually, I could see this data being used to generate a lot of the data for the simulation. Anything without a deathrattle or battlecry mechanic we could load directly from the json, and then we just need a mapping from a composite key of cardname+mechanic to an implementation.