Add CI/CD

[drunkbatya]

Added CI/CD for automatic build and push docker image to dockerhub. Build process will appear on the Github Hosted runners.

To make it work you need to provide 3 repository secrets: REGISTRY_LOGIN - login for dockerhub REGISTRY_PASSWORD - password for dockerhub IMAGE_NAME - fully-qualified name of image e.g. TradeMe/ReviewMe

Also i've changed build behavior in Dockerfile - passing repo files directly insted of installing some version, to make all version control on the github side.

Default strategy will be: Every commit to master branch will be pushed to $IMAGE_NAME:master, and every tag will be $IMAGE_NAME:$TAG_NAME.

Also, i've added creating separate data directory for persistent files - /var/lib/reviewme, now it used for storing only published_reviews.json.