Implement bake.test driver

[SanderMertens]

Implement a simple test framework as a bake driver (derived from https://github.com/cortoproject/corto-test). The test framework will do code generation of test cases and the code that invokes the test runner, and will allow for configuration of test suites and test cases from the JSON file:

{
    "id": "test",
    "type": "application",
    "value": {
        "public": false
    },
    "test": {
        "testsuites": [{
            "id": "my_first_suite",
            "testcases": [
                "tc_first_test",
                "tc_second_test",
                "tc_third_test"
            ]
        }]
    }
}