Set up gitignore.
Added Composer files.
Added basic PHPUnit files.
Created basically-empty class for actually doing the work.
Added unit test for initial functionality (which currently fails, since I haven't implemented it yet).
Implemented the basic functionality.
Added more unit tests.
Added fields to composer.json for use by Packagist.
Updated README.md.
Merge branch 'feature/basic-functionality' into develop