create rebar3 test profile

rebar.config

@@ -1,5 +1,4 @@
 {erl_opts, [debug_info]}.
-{cover_enabled, true}.
 
 {deps, [{cre, {git, "https://github.com/joergen7/cre.git", {branch, "master"}}},
         {effi, {git, "https://github.com/joergen7/effi.git", {branch, "master"}}},
@@ -11,6 +10,8 @@
 {escript_emu_args, "%%! -escript main cf_worker -connect_all false -sname cfl_wrk\n"}.
 {escript_name, "cfl_wrk"}.
 
+{profiles,
+ [{test, [{cover_enabled, true}]}]}.
 {dialyzer, [{warnings, [unmatched_returns,
                         error_handling,
                         underspecs]},