This commit makes sure that the parser considers the git-repos field
mandatory for automated tests.

It also updates one test file with a new test definition using
git-repos.

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>

This commit applies several changes in order to turn the
renderer code into a proper python module and command that
can be easily installed using the setuptools module.

Main changes:
- Main executable is named atc
- Use setuptools to install renderer executable
- Improve tests so they can be easily executed by packages
- Update README instructions

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>

This commit adds the unit test module for the renderer.

It includes tests for the parser, renderer and relevant formatting
methods. It also adds a set of files that are used by some of these
tests.

The commit also updates the README file explaining how to execute
these tests.

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>

- Update the README listing existing macros and how to
  use the renderer.
- Rename the main program to render-test-case
- Rename the tc directory to tests-cases

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>

This commit also adds a new macro 'macro_modules_preconditions'
to make convenient adding the preconditions for the library modules
test cases.

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>