Use the latest exchanger version

Author: florianv

composer.json

@@ -22,7 +22,7 @@
     },
     "require": {
         "php": "^5.5 || ^7.0",
-        "florianv/exchanger": "~0.3"
+        "florianv/exchanger": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8 || ^5.4",