Implement getServerMetadata method.

This method let the user get the unique name and public IP of its machine during a running session.
This let users implement their own communication method for Unreal app for example (using their own server to communicate with their app).

** Update readme

README.md

@@ -133,6 +133,22 @@ player.getServerAvailability(function(data) {
 });
 ```
 
+#### getServerMetadata(function(metadata) {}, function(error) {}) asynchronous function
+Call this function to get unique VM informations.
+This function return metadata only when a session is running.
+`metadata: Object`:
+- `publicIP: String` The VM public IP.
+- `name: String` A unique name to identify a VM.
+##### Example:
+```javascript
+player.getServerAvailability(function(metadata) {
+  console.log("Public VM IP: ", metadata.publicIP);
+  console.log("VM unique name: ", metadata.name);
+}, function(error) {
+  // Treat the error.
+});
+```
+
 ### Methods to create your own interface
 Those methods let you create your own interface.
 

classes/Player.js

@@ -28,7 +28,8 @@ const _eventNames = {
   ON_USER_INACTIVE: "onUserInactive",
   ON_SESSION_STOPPED: "onSessionStopped",
   ON_STATS: "onStats",
-  GET_SERVER_AVAILABILITY: "getServerAvailability"
+  GET_SERVER_AVAILABILITY: "getServerAvailability",
+  GET_SERVER_METADATA: "getServerMetadata",
 };
 
 const _qualityValues = {
@@ -205,6 +206,25 @@ module.exports = class Player {
           
           this._getServerAvailabilityCallback(response.stats);
           return;
+        case _eventNames.GET_SERVER_METADATA:
+          const response = e.data.value;
+
+          if (response.error) {
+            console.log("Error getting server metadata", response.error);
+            if (this._getServerMetadataErrorCallback) {
+              this._getServerMetadataErrorCallback(response.error);
+            }
+
+            return;
+          }
+
+          if (!this._getServerMetadataCallback) {
+            console.log("No success callback binded !");
+            return;
+          }
+          
+          this._getServerMetadataCallback(response.metadata);
+          return;
         case _eventNames.ERROR:
           this._displayErrorMessage(e.data.value);
           return;
@@ -366,4 +386,16 @@ module.exports = class Player {
     this.embed.contentWindow.postMessage({ type: _eventNames.GET_SERVER_AVAILABILITY }, _furioosServerUrl);
     // The response will be treat in the listener below.
   }
+
+  getServerMetadata(getServerMetadataCallback, getServerMetadataErrorCallback) {
+    if (!this.loaded) {
+      return; // Not loaded.
+    }
+    this._getServerMetadataCallback = getServerMetadataCallback;
+    this._getServerMetadataErrorCallback = getServerMetadataErrorCallback;
+
+    // Call the get.
+    this.embed.contentWindow.postMessage({ type: _eventNames.GET_SERVER_METADATA }, _furioosServerUrl);
+    // The response will be treat in the listener below.
+  }
 }