Switch to psr-4, closes #4531

composer.json

@@ -49,10 +49,10 @@
         "ext-openssl": "Enabling the openssl extension allows you to access https URLs for repositories and packages"
     },
     "autoload": {
-        "psr-0": { "Composer": "src/" }
+        "psr-4": { "Composer\\": "src/Composer" }
     },
     "autoload-dev": {
-        "psr-0": { "Composer\\Test": "tests/" }
+        "psr-4": { "Composer\\Test\\": "tests/Composer/Test" }
     },
     "bin": ["bin/composer"],
     "extra": {

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "c0ac13596dfaf0f6cb3e334074c3f17e",
+    "hash": "299aaabeb02408df8d77b7b8920cb1fe",
     "content-hash": "ef034b5b61856139fa515d678e2978fd",
     "packages": [
         {