1.8

Feature. Added 2 new checks for fingerprint headers: 'X-Nginx-Cache', 'X-Nextjs-Cache'.
Feature. Bump Python required version >= 3.6.
Feature. Check for incorrect 'Permission-Policy' values.
Feature. Added browser compatibility check for enabled security headers.
Fix. Improve info about "Deprecated Headers and Insecure values".
Fix. Improved HTTP 404 parsing (via "exceptions.ConnectionError").
Fix. Improve PDF output.
Minor. Add caniuse.com license details (CC-BY-4.0).
Minor. Add OWASP reference.
Minor. Update screenshots and sample files.