rename file: test_data.tar.gz

[petrrr]

This issue, to propose that the file with test data is renamed to be more specific to waveloc. Of cause, this is a very minor issue, but more specific names help to find and associate such file to the related software. One possibility could be waveloc_test_data.tar.gz or waveloc-test-data.tar.gz. Thanks for considering

[petrrr]

There is also the following file around: https://github.com/downloads/amaggi/waveloc/test_data.tgz name, checksum, size differ, is this one outdated? It appears in setup_examples.py