Merge pull request #46 from veewee/assert-v2

Allow webmozart/assert v2

Author: veewee

composer.json

@@ -31,7 +31,7 @@
         "psr/http-message": "^1.0 || ^2.0",
         "psr/http-message-implementation": "^1.0",
         "psr/log": "^3",
-        "webmozart/assert": "^1.11"
+        "webmozart/assert": "^1.11 | ^2.0"
     },
     "require-dev": {
         "guzzlehttp/guzzle": "^7.8",