Report a bit more information on unsupported github events (#299)

This will make it easier to add more events in the future.

Author: Zimmi48

bot-components/GitHub_subscriptions.ml

@@ -197,7 +197,7 @@ let github_action ~event ~action json =
   | "check_suite", "requested" ->
       Ok (CheckSuiteRequested (check_suite_info_of_json json))
   | _ ->
-      Ok (UnsupportedEvent "Unsupported GitHub action.")
+      Ok (UnsupportedEvent (f "Unsupported GitHub action %s / %s." event action))
 
 let github_event ~event json =
   match event with
@@ -224,7 +224,7 @@ let github_event ~event json =
       | ref_type ->
           Error (f "Unexpected ref_type: %s" ref_type) )
   | _ ->
-      Ok (UnsupportedEvent "Unsupported GitHub event.")
+      Ok (UnsupportedEvent (f "Unsupported GitHub event %s." event))
 
 let receive_github ~secret headers body =
   let open Result.Monad_infix in