Dereference symbolic links when copying files in the compilation

The `test_SUITE_data` folder when running common test is only
dereference when the folder is in the root app. When the folder
is in `apps/{app-name}/test`, the folder is copied in compilation time.
The first approach to fix it was added here [1].

[1] erlang#2731

apps/rebar/src/rebar_prv_compile.erl

@@ -503,7 +503,7 @@ copy(Source, Target) ->
     {ok, Files} = rebar_utils:list_dir(Source),
     case [filename:join([Source, F]) || F <- Files] of
         []    -> ok;
-        Paths -> rebar_file_utils:cp_r(Paths, Target)
+        Paths -> rebar_file_utils:cp_r(Paths, Target, [{dereference, true}])
     end.
 
 delete_if_symlink(Path) ->