Adopting Modern Objective-C for enum

SocketRocket/SRWebSocket.h

@@ -17,12 +17,12 @@
 #import <Foundation/Foundation.h>
 #import <Security/SecCertificate.h>
 
-typedef enum {
+typedef NS_ENUM(NSInteger, SRReadyState) {
     SR_CONNECTING   = 0,
     SR_OPEN         = 1,
     SR_CLOSING      = 2,
     SR_CLOSED       = 3,
-} SRReadyState;
+};
 
 typedef enum SRStatusCode : NSInteger {
     SRStatusCodeNormal = 1000,