From (1118a2a5104777c2851d705c9d36f18b063b3245) puzzle supports [version 2](https://docs.docker.com/compose/compose-file/#/version-2) of docker-compose. Whenever Puzzle detects an v2 base compose-file, it parses it and produces an version 2 docker-compose. If the base compose is a v1, the version is mantained.
