Implement tracking of referrals (#659)

* Implement tracking of referrals

This also modifies (or fixes) auto-joining.

src/RtsClient.js

@@ -12,4 +12,32 @@ export default class RtsClient {
             json: true,
         });
     }
+
+    /**
+     * Track a referral with the Riot Team Server. This should be called once a referred
+     * user has been successfully registered.
+     * @param {string} referrer the user ID of one who referred the user to Riot.
+     * @param {string} user_id the user ID of the user being referred.
+     * @param {string} user_email the email address linked to `user_id`.
+     * @returns {Promise} a promise that resolves to [$response, $body], where $response
+     * is the response object created by the request lib and $body is the object parsed
+     * from the JSON response body. $body should be { team_token: 'sometoken' } upon
+     * success.
+     */
+    trackReferral(referrer, user_id, user_email) {
+        return request({
+            url: this._url + '/register',
+            json: true,
+            body: {referrer, user_id, user_email},
+            method: 'POST',
+        });
+    }
+
+    getTeam(team_token) {
+        return request({
+            url: this._url + '/teamConfiguration',
+            json: true,
+            qs: {team_token},
+        });
+    }
 }