Bump guzzle adapter

Author: alexw23

composer.json

@@ -12,7 +12,7 @@
         "php": ">=5.4.0",
         "illuminate/support": "~5|~6",
         "omnipay/common": "~3.0",
-        "php-http/guzzle6-adapter": "^1"
+        "php-http/guzzle6-adapter": "^1.1|^2"
     },
     "autoload": {
         "psr-0": {