url: http://localhost:3000/orderbook
  params:
    id: string (required)
    symbol: string (required)

  response: {
    bids": [
      [
        0.08184,
        6
      ],
      ...
    ]
  }

  url: http://localhost:3000/orderbook
  params:
    id: kraken
    symbol: BCH/BTC

  url: http://localhost:3000/symbols
  params:
    id: string (required)

  response: [
    "ADA/BTC",
    "ADA/CAD",
    "ADA/ETH",
    "ADA/EUR",
    ...
  ]

  url: http://localhost:3000/symbols
  params:
    id: bxinth

  url: http://localhost:3000/ticker
  params:
    id: string (required)
    symbol: string (required)

  response: {
    "symbol": "BCH/BTC",
    "timestamp": 1538148033751,
    ...
  }

  url: http://localhost:3000/ticker
  params:
    id: kraken
    symbol: BCH/BTC

  url: http://localhost:3000/balance
  params:
    id: string (required)
    apiKey: string (required)
    secret: string (required)

  response: {
    "symbol": "BCH/BTC",
    "timestamp": 1538148033751,
    ...
  }

  url: http://localhost:3000/balance
  params:
    id: bxinth
    apiKey: 484a63e83ccd
    secret: 80c6c46d100a

  url: http://localhost:3000/placeOrder
  params:
    id: string (required)
    symbol: string (required)
    orderType: string (required)
    side: string (required - buy | sell)
    amount: number (required)
    price: number (required)
    apiKey: string (required)
    secret: string (required)

  response: {
    ...error, need verification
  }

  url: http://localhost:3000/placeOrder
  params:
    id: bxinth
    symbol: BTC/THB
    orderType: limit
    side: sell
    amount: 0.321
    price: 100
    apiKey: 484a63e83ccd
    secret: 80c6c46d100a