fix: Request defaults not set when using Agent, issue #214.

Author: bkuker

Diff for: lib/request.js

@@ -339,7 +339,7 @@ methods.forEach(function(method){
       // https://tools.ietf.org/html/rfc6454#section-3
       req.withCredentials();
     }
-
+    this._setDefaults(req);
     return req;
   };
 });