Fluentd

Modified fluentd image for UW usage

It builds upon https://github.com/fluent/fluentd-docker-image using plugin versions from https://github.com/fluent/fluentd-kubernetes-daemonset 's debian-s3 images (like https://github.com/fluent/fluentd-kubernetes-daemonset/blob/master/docker-image/v1.14/debian-s3/Gemfile)

We use debian-s3 since it's the closest to what we want, and we can rely on their plugin versions combination to work, while only adding a few plugins ourselves

Updating the image

• Update the fluent/fluend image tag in Dockerfile
• Update UpstreamGemfile pulling from upstream
• Update versions in UWGemfile, checking plugin's releases