fix tar provider to pass release and tar to relx as 2 commands

rebar.config

@@ -36,7 +36,7 @@
          {branch, "master"}}},
        {relx, "",
         {git, "https://github.com/tsloughter/relx.git",
-         {branch, "ec_git_vsn"}}},
+         {branch, "master"}}},
        {getopt, "", {git, "https://github.com/jcomellas/getopt.git", {branch, "master"}}}]}.
 
 {erlydtl_opts, [{doc_root, "priv/templates"},

src/rebar_prv_tar.erl

@@ -34,9 +34,9 @@ init(State) ->
 do(State) ->
     case rebar_state:get(State, relx, []) of
         [] ->
-            relx:main(["release tar"]);
+            relx:main(["release class="s">", "tar"]);
         Config ->
-            relx:main([{config, Config}], ["release tar"])
+            relx:main([{config, Config}], ["release class="s">", "tar"])
     end,
     {ok, State}.