There's lots of (YAML) test data that is just trivial configurations
for modules. Since the configurations themselves are **also** CC0-1.0,
and the tests are less interesting, license them equally liberally.
- create directories for new tests ahead of the tests themselves;
this **can** still cause problems if a test is run standalone.
- if creating the grub-dir at runtime is necessary, be informative
if it fails.
- The Python configuration tests sometimes need extra setup, so
do that through a CMakeTests.txt file in the test directory.
- Patch up existing tests:
- grubcfg needs /tmp/calamares/etc/default to exist
- rawfs won't work on FreeBSD because of differences in /proc
