TODO: Add description
To run the application
iex -S mix AggregatorActor.start_link KrakenClient.start_link [{:"ETH/USD", "ETH_USD"}]
HuobiClient.start_link [{:btcusdt, "btc_usdt"}]
the convention is start_link takes an array of tuples, the first element of the tuple is an atom, which corresponds to the string used to subscribe to the tickers and the second element is the symble snaked-cased