Add osiris.app.src file

Fixes compilation with `rebar3`

src/osiris.app.src

@@ -0,0 +1,16 @@
+{application,osiris,
+             [{description,"Foundation of the log-based streaming subsystem for RabbitMQ"},
+              {vsn,"1.8.1"},
+              {licenses,["Apache-2.0","MPL-2.0"]},
+              {links,[{"github","https://github.com/rabbitmq/osiris"}]},
+              {modules,[osiris,osiris_app,osiris_bench,osiris_bloom,
+                        osiris_counters,osiris_ets,osiris_log,
+                        osiris_log_shared,osiris_member,osiris_replica,
+                        osiris_replica_reader,osiris_replica_reader_sup,
+                        osiris_retention,osiris_server_sup,osiris_sup,
+                        osiris_tracking,osiris_util,osiris_writer]},
+              {registered,[ra_sup]},
+              {applications,[kernel,stdlib,sasl,crypto,gen_batch_server,
+                             seshat]},
+              {mod,{osiris_app,[]}},
+              {env,[]}]}.