Update README files for Slick and Doobie INT tests

[miroslavpojer]

Background

The project contains integration tests for Slick and Doobie modules.
These tests need some preparation steps to be able to run.
These steps are not well documented.
I tried to get them running and I failed on missing troubleshooting chapter and on missing test data inserts.
So the tests are failing.

Feature

• Update both README files to provide a list of steps to get tests running.
• Provide the SQL file content with INSERT to the empty DB.

[lsulak]

Closing as done in the #118 and if there is more need to add something more, we can always reopen this.