Verify secure coding for YYImage.

YYImage/YYImage.m

@@ -212,6 +212,10 @@ static CGFloat _NSStringPathScale(NSString *string) {
     }
 }
 
++ (BOOL)supportsSecureCoding {
+    return  YES;
+}
+
 #pragma mark - protocol YYAnimatedImage
 
 - (NSUInteger)animatedImageFrameCount {