As the REST API is a part of the core, it is more appropriate for the
tests to reside there as well. Further refactoring of the testing needs to
be done to allow multiple components to use the same framework but with
different tests.
The tests now automatically start MaxScale before each test block and stop
it and perform cleanup after the test. This is done by simply calling the
`before.sh` and `after.sh` scripts before each test block.
