Improve support for integration tests on SQLFeatureStore

[tfr42]

Currently it requires some efforts to run integration tests against a PostgreSQL/PostGIS DB.
Expected is to have a lightweight infrastructure to create a fresh clean database for testing.
It requires some research if in-memory databases such as h2, hsqldb can be used or docker container with PostgreSQL started by Maven.
The latter would require at least two profiles, one for travis-ci where docker container with postgreSQL is available and a local development environment.

[tfr42]

See PR #665

[tfr42]

For testing deegree against different DBMS backends the usage of docker containers is the preferred way.
And the maven build should not start and stop those containers. Here a build pipeline shall execute system and acceptance tests against this infrastructure.

[tfr42]

WIP is https://github.com/tfr42/deegree3/blob/feature/addJenkinsfile/Jenkinsfile
and see #651 for more about how we want to improve the build process

[tfr42]

The build pipeline using the Jenkinsfile is in use. Docker has been installed on the build server.

[stempler]

Did you already select a tool/library for integrating the containers in the tests? I can recommend testcontainers.