Initial changes towards HitBTC v2 api and websocket *INCOMPLETE*

[jaysonsantos]

Hi, the v1 API and web sockets from HitBTC seem to be broken so I started this branch to move to the v2. They changed the return types on v1 for trades too, the interface used to expect number but now it returns strings. I want to test cancel and add orders but I could not find a way to post order (with some absurd number so no one would buy or sell because they have no demo API yet), could you help me with that? Could you also take a look at what I did to check if it seems right? Thanks!