Merge pull request #36 from php-http/httplug-20

Allow httplug 2.0

Author: dbu

composer.json

@@ -17,7 +17,7 @@
     "require": {
         "php": ">=5.4",
         "phpunit/phpunit": "^4.8.35 || ^5.4.3 || ^6.0",
-        "php-http/httplug": "^1.0",
+        "php-http/httplug": "^1.0 || ^2.0",
         "php-http/message": "^1.0",
         "guzzlehttp/psr7": "^1.0",
         "th3n3rd/cartesian-product": "^0.3"