fix compile errors for Xcode 9.1 beta

Sources/CSListObserver.swift

@@ -42,7 +42,7 @@ import CoreData
  */
 @available(OSX 10.12, *)
 @objc
-public protocol CSListObserver: class, AnyObject {
+public protocol CSListObserver: class {
     
     /**
      Handles processing just before a change to the observed list occurs

Sources/CSObjectObserver.swift

@@ -40,7 +40,7 @@ import CoreData
  */
 @available(OSX 10.12, *)
 @objc
-public protocol CSObjectObserver: class, AnyObject {
+public protocol CSObjectObserver: class {
     
     /**
      Handles processing just before a change to the observed `object` occurs

Sources/CoreDataNativeType.swift

@@ -33,7 +33,7 @@ import CoreData
  Objective-C Foundation types that are natively supported by Core Data managed attributes all conform to `CoreDataNativeType`.
  */
 @objc
-public protocol CoreDataNativeType: class, NSObjectProtocol, AnyObject {}
+public protocol CoreDataNativeType: class, NSObjectProtocol {}
 
 
 // MARK: - NSNumber

Sources/CoreStoreBridge.swift

@@ -31,7 +31,7 @@ import Foundation
 /**
  `CoreStoreObjectiveCType`s are Objective-C accessible classes that represent CoreStore's Swift types.
  */
-public protocol CoreStoreObjectiveCType: class, AnyObject {
+public protocol CoreStoreObjectiveCType: class {
     
     /**
      The corresponding Swift type