Threaded message improvements

Sources/NetworkInterface.swift

@@ -205,15 +205,4 @@ public struct NetworkInterface {
             return "slackkit.boundary.\(arc4random())\(arc4random())"
         #endif
     }
-
-    // MARK: - Filter Nil Parameters
-    private func filterNilParameters(_ parameters: [String: Any?]) -> [String: Any] {
-        var finalParameters = [String: Any]()
-        for (key, value) in parameters {
-            if let unwrapped = value {
-                finalParameters[key] = unwrapped
-            }
-        }
-        return finalParameters
-    }
 }

Sources/WebAPI.swift

@@ -225,6 +225,7 @@ extension WebAPI {
         channel: String,
         thread: String,
         text: String,
+        broadcastReply: Bool = false,
         username: String? = nil,
         asUser: Bool? = nil,
         parse: ParseMode? = nil,
@@ -242,6 +243,7 @@ extension WebAPI {
             "channel": channel,
             "thread_ts": thread,
             "text": text.slackFormatEscaping,
+            "broadcastReply": broadcastReply,
             "as_user": asUser,
             "parse": parse?.rawValue,
             "link_names": linkNames,