ex_doc dependency for Erlang users

[goncalotomas]

Hi,

I've been using eredis_cluster for a while now (here). Thanks for making it available!

I noticed that you added ex_doc and removed the , only :dev: https://github.com/adrienmo/eredis_cluster/commit/4192b3c12c57d60253e1a474853f36e8babb0166#diff-6023be6004fce4718dad3dafb576d258

Since I'm having trouble making this compile with version 0.5.12 on Erlang (using OTP 21 and rebar3 3.9.0), would you consider moving the ex_doc dependency back to a separate profile?

I tried using rebar_mix, got some errors that I am trying to work around but I would still appreciate having one less dependency that is not strictly required :)

Thanks.

[NobbZ]

Another question based on this, why at all are there mix and rebar files around?

Please choose one over the other (as this is erlang, perhaps choose rebar) and stick to that.

You can push/publish to hex using rebar as well.