port lz4 compression feature back to 2.x versions

[zmstone]

lz4 was added in version 3.1
brod is still not upgraded yet.
it would be nice to have lz4 ported back to 2.x version.

the lz4 support can be done as a static rebar3 dependency.

[emeryotopalik]

@zmstone Do you have any idea when this will be added?

[zmstone]

brod has been upgraded to depend on latest version kafka_protocol.

however lz4 is not added as a dependency of brod, so the wrapping project which uses brod as a dependency should also provide lz4 lib.
for more details, see https://github.com/kafka4beam/kafka_protocol/blob/master/README.md#compression-support