Use 8.7.x as TYPO3 core version

composer.json

@@ -23,7 +23,7 @@
     }
   ],
   "require": {
-    "typo3/cms": "8.7.1",
+    "typo3/cms": "^8.7",
     "helhum/typo3-console": "^4.5",
     "dmitryd/typo3-realurl": "^2.2",
     "apache-solr-for-typo3/solr": "^6.0",