S3Proxy 2.1.0

• Add Access-Control-Allow-Credentials header, #416
• Clear system property for credentials for file paths, #546
• Ensure all errors are logged at debug level, #543
• Fixed marker being saved under wrong key in marker cache, #531
• Ignore x-amz-api-version, #497
• Improve Docker configuration, #420, #441, #505, #512, #513
• Require Java 11, #458
• Upgrade to Jetty 11, #457

Thanks @christophkreutzer, @Decard6, @kinoute, @larshagencognite, @ryanfaircloth, @srujandeshpande, @st-h, and @thiagodasilva for opening pull request to improve S3Proxy!