Fix mongo-adapter and PyYAML dependency issues. Improved Dockerfile

[1.6]

Changed

• Build and use local Dockerfile when creating demo container in docker-compose
• Minify Docker image by adding a multi-stage build and manually installing Picard and the Java Virtual Machine
• Speed up Docker image building by basing it on another image with cyvcf2 already installed

Fixed

• Parse yaml config files using yaml.safe_load to avoid missing Loader error due to deprecation introduced by PyYAML 6.0
• Typo in docker-compose file
• Fix mongo-adapter dependency to use version>=0.3.3. Previous versions have a way too short connection timeout and approximate URI log print