Adds possiblity to select different databases.

THis currently only enables MySQL and PostgreSQL. Even though MariaDB is
also as possibility given it is currently not supported!
Adds actual vagrant config for postgresql

This adds the actual config for adding a postgresql-database.
Fixes and adds tests

This commit fixes the existing database-test and adds an aditional test
to check for PostgreSQL preparation
Fixes issues with database-roles and adds mariaDB

This commit adds MariaDB.

Also some issues with database-setup have been eliminated
Adds two more tests
Fixes CodeReview-Issues and adds tests
Merge pull request #75 from heiglandreas/feature/addDifferentDBs

Adds possiblity to select different databases.