Update dependency eslint-plugin-react to v7.20.1

Author: renovate-bot

package.json

@@ -53,7 +53,7 @@
     "codemirror": "5.53.2",
     "css-loader": "3.6.0",
     "eslint": "6.8.0",
-    "eslint-plugin-react": "7.5.1",
+    "eslint-plugin-react": "7.20.1",
     "extract-text-webpack-plugin": "3.0.2",
     "file-loader": "6.0.0",
     "image-webpack-loader": "6.0.0",