Update dependency eslint to v7

Author: renovate-bot

package-lock.json

@@ -43,7 +43,7 @@
     "cssnano": "4.1.10",
     "cz-conventional-changelog": "3.0.2",
     "documentation": "13.0.1",
-    "eslint": "6.8.0",
+    "eslint": "7.1.0",
     "eslint-config-unobtrusive": "1.2.5",
     "eslint-plugin-babel": "5.3.0",
     "extract-loader": "5.0.1",