implement PSR-3 logging

Author: estebangarcia

EchoLogger.php

@@ -0,0 +1,17 @@
+<?php
+
+
+namespace Binance;
+
+
+use Psr\Log\AbstractLogger;
+
+class EchoLogger extends AbstractLogger
+{
+
+    public function log($level, $message, array $context = array())
+    {
+        $format = "[%s][%s] - %s";
+        echo sprintf($format, date("Y-m-d H:i:s"), $level, $message);
+    }
+}

composer.json

@@ -12,7 +12,8 @@
         "ext-curl": "*",
         "ratchet/pawl": "^0.3.0",
         "react/socket": "^1.0 || ^0.8 || ^0.7",
-        "ratchet/rfc6455": "^0.3"
+        "ratchet/rfc6455": "^0.3",
+        "psr/log": "^1.1"
     },
     "require-dev": {
         "phpunit/phpunit": "~6",