Update dependency eslint to v7

Author: renovate-bot

package.json

@@ -12,7 +12,7 @@
     "@testing-library/react": "9.4.1",
     "babel-loader": "8.0.6",
     "css-loader": "3.4.2",
-    "eslint": "6.8.0",
+    "eslint": "7.12.1",
     "eslint-config-standard": "12.0.0",
     "eslint-config-standard-react": "7.0.2",
     "eslint-plugin-import": "2.17.3",