feat(api): add orderbook api

 Get order book data.

src/server/routes/api.js

@@ -10,6 +10,7 @@ exports.getOrders = getOrders;
 exports.getPositions = getPositions;
 exports.getTransactions = getTransactions;
 exports.getCalendar = getCalendar;
+exports.getOrderbook = getOrderbook;
 exports.putOrder = putOrder;
 exports.closeOrder = closeOrder;
 exports.closeTrade = closeTrade;
@@ -237,6 +238,32 @@ function getCalendar(req, response) {
     });
 }
 
+function getOrderbook(req, response) {
+    var environment,
+        token;
+
+    if (!req.body) {
+        return response.sendStatus(400);
+    }
+
+    environment = req.body.environment || credentials.environment;
+    token = req.body.token || credentials.token;
+
+    throttledRequest({
+        "url": config.getUrl(environment, "api")
+            + "/labs/v1/orderbook_data",
+        qs: {
+            instrument: req.body.instrument || "EUR_USD",
+            period: req.body.period || 3600
+        },
+        "headers": {
+            "Authorization": "Bearer " + token
+        }
+    }, function (err, res, body) {
+        processApi("getOrderbook", err, body, response);
+    });
+}
+
 function putOrder(req, response) {
     var environment,
         token,

src/server/routes/index.js

@@ -23,6 +23,7 @@ router.post("/orders", jsonParser, api.getOrders);
 router.post("/positions", jsonParser, api.getPositions);
 router.post("/transactions", jsonParser, api.getTransactions);
 router.post("/calendar", jsonParser, api.getCalendar);
+router.post("/orderbook", jsonParser, api.getOrderbook);
 router.post("/order", jsonParser, api.putOrder);
 router.post("/closeorder", jsonParser, api.closeOrder);
 router.post("/closetrade", jsonParser, api.closeTrade);