Added support of version 2+ of php-http/client-common (#280)

Signed-off-by: Julien Bonvarlet <[email protected]>

Author: tyloo

composer.json

@@ -27,7 +27,7 @@
         "php-http/discovery": "^1.4",
         "php-http/message": "^1.7",
         "psr/http-message": "^1.0",
-        "php-http/client-common": "^1.9"
+        "php-http/client-common": "^1.9 || ^2.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^7.0",