Added more transaction helpers

Author: spamoom

src/Transaction.php

@@ -11,12 +11,25 @@ public function __construct($transaction)
         $this->transaction = $transaction;
     }
 
+    public function removeQueryStringFromUrl()
+    {
+        $pathParts = explode('?', $this->transaction->fullPath);
+        $this->transaction->fullPath = $pathParts[0];
+    }
+
     public function replaceInPath($old, $new)
     {
         $this->transaction->request->uri = str_replace($old, $new, $this->transaction->request->uri);
         $this->transaction->fullPath = str_replace($old, $new, $this->transaction->fullPath);
     }
 
+    public function alterBody(\Closure $closure)
+    {
+        $requestBody = json_decode($this->transaction->request->body);
+        $requestBody = $closure($requestBody);
+        $this->transaction->request->body = json_encode($requestBody);
+    }
+
     /**
      * Sets a HTTP header
      * @param $header