create rebar3 test profile

rebar.config

@@ -1,15 +1,22 @@
 {erl_opts, [debug_info]}.
-{cover_enabled, true}.
+
 {deps, [{getopt, "1.0.3"},
         {jsone, "1.9.0"}]}.
+
 {escript_incl_apps, [getopt, jsone]}.
+
+{profiles,
+ [{test, [{cover_enabled, true}]}]}.
+
 {dialyzer, [{warnings, [unmatched_returns,
                         error_handling,
                         underspecs]},
             {plt_extra_apps, [getopt, jsone]}]}.
+
 {xref_checks, [undefined_function_calls,
                undefined_functions,
                locals_not_used,
                deprecated_function_calls,
                deprecated_functions]}.
+
 {project_plugins, [covertool, rebar3_efmt]}.