Merge pull request #2379 from Nyholm/psr-log

Make sure we dont use Psr\Log\LogLevel since we don't require it in mposer

src/Middleware.php

@@ -7,7 +7,6 @@
 use GuzzleHttp\Psr7;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Log\LoggerInterface;
-use Psr\Log\LogLevel;
 
 /**
  * Functions used to create and wrap handlers with handler middleware.
@@ -183,7 +182,7 @@ public static function retry(callable $decider, callable $delay = null)
      *
      * @return callable Returns a function that accepts the next handler.
      */
-    public static function log(LoggerInterface $logger, MessageFormatter $formatter, $logLevel = LogLevel::INFO)
+    public static function log(LoggerInterface $logger, MessageFormatter $formatter, $logLevel = 'info' /* \Psr\Log\LogLevel::INFO */)
     {
         return function (callable $handler) use ($logger, $formatter, $logLevel) {
             return function ($request, array $options) use ($handler, $logger, $formatter, $logLevel) {