Installing PostgreSQL

PostgreSQL (https://www.postgresql.org/) is a powerful and popular open source SQL database. Even though it has nothing to do with Continuous Integration, we will need it to install the next tool, SonarQube. We will make use of PostgreSQL in the later chapters of the book, so we are not going through all this trouble just for SonarQube (but trust me, SonarQube alone is already worth it!).