Compressed SSZ files used in unit test need to be related

[rodrigo-o]

We have 2 ssz files as fixtures, one for the beacon state and another one for an empty block, the two appear to be related and picking any two of those fail a specific test:

  1) test construct block (Unit.Validator.BlockBuilderTest)
     test/unit/validator/block_builder_test.exs:21
     Assertion with == failed
     code:  assert block.body.randao_reveal == spec_block.message.body.randao_reveal
     left:  "\x97M_\x1D\xBB\xC5\xF5\xE5QW]^\xEFԼxl\x13Y\xB80\xA8x\xC8\xDDK\xAEP9\x91\xF8\x92\x10\xB6\xF1\xF8\x8Cpdw\xD7A\x8A\x86\x05$\xC0\xFF\x14\x1C\xE1\xF4`\xB6\x96BU\xCB\x18\xD0\xF4\xBE\xD0F\x92\xE3ka\xE7)U\e\x9A\x8F-.o\xC1\xA4$\xC3\xD4-\xBD`\x89l\xB6\xED\xFD\xD8\tG\x9C\xFB\xC5"
     right: "?\xAD\xB5\xBE\xE4\xD4_\xF7\x01eE\x15W\x9F\x13\xE4$\xA8\x82\x89r\x97\xBF\vb\xFB}(\xDE(\xAC\xBCHy\xD2wZ\x0E\x0Ew)=*\xD3\"\xED\xC5S\xA4\x04\xEDʪ\xF7ɯ\xFB\tg\e\xD4޺[`D\x82>VE\x8D\x8F\xB4C\xBE/\xED\xCD\r\x9C\d}5\xB4\xD4\x13l9\xFFӻ*i\xD7\xF0\xD8"
     stacktrace:
       test/unit/validator/block_builder_test.exs:59: (test)