Added dockerfile to test installation of pljava and sep3 tools

[tfr42]

This PR adds a dockerfile for testing purposes. The dockerfile uses postgis/postgis as base image and installs pljava and sep3 tools.

[tfr42]

@wanhoff Please review and add comments

[wanhoff]

Hi @tfr42,

I created a docker container to run sep3 tools as well, so I guess we should integrate some stuff to your code. I notice some differences:

• I used postgres without postgis. SEP3 should not need postgis
• I implemented the shell script functions in a different way:
  • user, password and database are set in Dockerfile ENV variables
  • I decided to do the psql and java stuff in a sql file that is executed on container startup

I would add my changes to the branch.
I have not yet worked with combined java and docker projects, but I assume the sql file should go to /src/main/resources, right?

I have some more features for the docker image, but would add these later.

[tfr42]

Hi @tfr42,

I created a docker container to run sep3 tools as well, so I guess we should integrate some stuff to your code. I notice some differences:

* I used postgres without postgis. SEP3 should not need postgis

We use the container also as backend DB for deegree WFS with BML schema mapping. This requires PGIS and we would like to keep the PG extension pre-installed.

* I implemented the shell script functions in a different way:
  
  * user, password and database are set in Dockerfile ENV variables

The script uses the default environment variables used by psql, see https://www.postgresql.org/docs/current/libpq-envars.html

  * I decided to do the psql and java stuff in a sql file that is executed on container startup

Just push a new branch with your changes and we will compare.

I would add my changes to the branch. I have not yet worked with combined java and docker projects, but I assume the sql file should go to /src/main/resources, right?

Dockerfile and related ressource can be placed in the root directory, which is supported by docker maven plugin

I have some more features for the docker image, but would add these later.