Bump html-validator from 5.1.4 to 5.1.5

Bumps [html-validator](https://github.com/zrrrzzt/html-validator) from 5.1.4 to 5.1.5.
- [Release notes](https://github.com/zrrrzzt/html-validator/releases)
- [Commits](zrrrzzt/html-validator@5.1.4...5.1.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -61,7 +61,7 @@
     "eslint": "^6.8.0",
     "fs-extra": "^8.1.0",
     "fs-walk": "0.0.2",
-    "html-validator": "^5.1.4",
+    "html-validator": "^5.1.5",
     "htmlencode": "0.0.4",
     "lockfile-lint": "^4.1.0",
     "mocha": "^7.1.0",