utils.kci_test: rename test_dict as group_dict
utils.kci_test: rename test_dict as group_dict

Rename test_dict as group_dict since it contains the data for a test
group rather than a test case.

Signed-off-by: Guillaume Tucker <e7e20b7c30f19d4ca6b81319ef81bf200369d137@collabora.com>

kernelci/kernelci-backend,kernelci/kernelci-backend