Update eunit_formatters to latest.

rebar.config

@@ -10,7 +10,7 @@
         {relx,                "3.23.1"},
         {cf,                  "0.2.2"},
         {cth_readable,        "1.3.0"},
-        {eunit_formatters,    "0.3.1"}]}.
+        {eunit_formatters,    "0.4.0"}]}.
 
 {post_hooks, [{"(linux|darwin|solaris|freebsd|netbsd|openbsd)",
                escriptize,