The change of the pets list in the owner to a Set makes it not
possible to use the pet's ids in the tests. Therefore, this commit
removes id comparisons for pets.

The project dependencies have been updated, including a change from
WildFly 8.2.1 to 10.1.0. This change affects the project configuration
in several ways, specially in tests configuration.

The README.md file has been updated to reflect the configuration
changes.

Some test classes have been refactorized for a more consistent use of
the OwnersDataset class and for a simpler test implementation.

The REST layer has been added but with incomplete tests. Students will
have to complete the tests.

This commit includes an important refactorization regarding tests. Test
classes and datasets have been moved from the "service" project to a new
"tests" project. This way, any project can include this "tests" project
as a dependency in order to have access to these common testing
resources.