remove phpcov dep

Author: andrew-nuwber

composer.json

@@ -21,7 +21,6 @@
   },
   "require-dev": {
     "phpunit/phpunit": "^8.0 || ^9.0",
-    "phpunit/phpcov": "^8.0 || ^9.0",
     "php-http/guzzle6-adapter": "^1.0",
     "mockery/mockery": "^1.3",
     "nyholm/nsa": "^1.0",