Add env, maintainers, licenses properties

src/emqttd.app.src

@@ -3,6 +3,10 @@
     {vsn, "2.1.0"},
     {modules, []},
     {registered, [emqttd_sup]},
-	{applications, [kernel,stdlib,gproc,lager,esockd,mochiweb,lager_syslog]},
+    {applications, [kernel,stdlib,gproc,lager,esockd,mochiweb,lager_syslog,pbkdf2]},
+    {env, []},
     {mod, {emqttd_app, []}}
+    {maintainers, ["Feng Lee <feng@emqtt.io>"]},
+    {licenses, ["MIT"]},
+    {links, [{"Github", "https://github.com/emqtt/emqttd"}]}
 ]}.