WIP: initial prototype

- Do not serilize keys with undefined values in querystring
- Added promises support in Transport.request

lib/Transport.js

@@ -34,10 +34,21 @@ class Transport {
   }
 
   request (params, options, callback) {
+    options = options || {}
     if (typeof options === 'function') {
       callback = options
       options = {}
     }
+
+    // promises support
+    if (callback == null) {
+      return new Promise((resolve, reject) => {
+        this.request(params, options, (err, result) => {
+          err ? reject(err) : resolve(result)
+        })
+      })
+    }
+
     callback = once(callback)
     // TODO: return in the result the metadata
     const meta = {