Removed unused composer dependency.

Author: derpaschi

composer.json

@@ -22,8 +22,7 @@
   ],
   "require": {
     "php": ">=7.1",
-    "composer-plugin-api": "^1.0 || ^2.0",
-    "oscarotero/env": "^2.1"
+    "composer-plugin-api": "^1.0 || ^2.0"
   },
   "require-dev": {
     "composer/composer": "1.6.* || 2.0.*@dev",