correct edgeFunction key and add middlewareSettings (#147)

Author: prayansh

Sources/Segment/Settings.swift

@@ -10,8 +10,9 @@ import Foundation
 public struct Settings: Codable {
     public var integrations: JSON? = nil
     public var plan: JSON? = nil
-    public var edgeFunctions: JSON? = nil
-    
+    public var edgeFunction: JSON? = nil
+    public var middlewareSettings: JSON? = nil
+
     public init(writeKey: String, apiHost: String) {
         integrations = try! JSON([
             SegmentDestination.Constants.integrationName.rawValue: [
@@ -34,13 +35,15 @@ public struct Settings: Codable {
         let values = try decoder.container(keyedBy: CodingKeys.self)
         self.integrations = try? values.decode(JSON.self, forKey: CodingKeys.integrations)
         self.plan = try? values.decode(JSON.self, forKey: CodingKeys.plan)
-        self.edgeFunctions = try? values.decode(JSON.self, forKey: CodingKeys.edgeFunctions)
+        self.edgeFunction = try? values.decode(JSON.self, forKey: CodingKeys.edgeFunction)
+        self.middlewareSettings = try? values.decode(JSON.self, forKey: CodingKeys.middlewareSettings)
     }
 
     enum CodingKeys: String, CodingKey {
         case integrations
         case plan
-        case edgeFunctions
+        case edgeFunction
+        case middlewareSettings
     }
 
     /**