Add esdl2.app for rebar3 compatibility

Author: zsoci

ebin/esdl2.app

@@ -0,0 +1,9 @@
+{application, 'esdl2', [
+	{description, "SDL2 Erlang NIF."},
+	{vsn, "0.1.0"},
+	{modules, ['esdl2','esdl2_app','esdl2_callbacks','esdl2_sup','sdl','sdl_clipboard','sdl_cpu_info','sdl_events','sdl_filesystem','sdl_gl','sdl_hints','sdl_keyboard','sdl_power','sdl_renderer','sdl_surface','sdl_texture','sdl_version','sdl_window']},
+	{registered, [esdl2_sup]},
+	{applications, [kernel,stdlib]},
+	{mod, {esdl2_app, []}},
+	{env, []}
+]}.