added proper configuration using aero

resources/config.edn

@@ -0,0 +1,12 @@
+{
+ :webserver ;; possible config from http-kit's run-server
+   {:port #long #or [#env PORT 8080]
+    :ip "0.0.0.0"
+    :max-body 524288 ;; 512kb, small but enough
+    :max-ws 524288}
+
+ :securities ;; list of tradable securities
+   [{:sec-id :foo}
+    {:sec-id :bar}
+    {:sec-id :toto}
+    {:sec-id :tata}]}