Always use LZ4 compression when running tests
JSROOT (used for #18 (closed)) doesn't support LZMA compression. As it doesn't really matter for the tests the tests should be modified to always use LZ4 compression.
JSROOT (used for #18 (closed)) doesn't support LZMA compression. As it doesn't really matter for the tests the tests should be modified to always use LZ4 compression.