Remove compile warning and bumping version to 0.0.2

Classes/UINavigationBar+MLNavigationBarTransition.m

@@ -34,8 +34,6 @@ - (UIView*)ml_backIndicatorView {
 }
 
 - (UILabel*)ml_backButtonLabel {
-    UINavigationItem *backItem = self.backItem;
-
     UILabel *label = nil;
     @try {
         UIView *backButtonView = [self.backItem valueForKey:@"_backButtonView"];

Classes/UINavigationController+MLNavigationBarTransition.m

@@ -40,6 +40,9 @@ + (void)load {
         BOOL valid = mlnbt_exchangeInstanceMethod(self, @selector(setNavigationBarHidden:), @selector(_mlnbt_setNavigationBarHidden:))&&
         mlnbt_exchangeInstanceMethod(self, @selector(setNavigationBarHidden:animated:), @selector(_mlnbt_setNavigationBarHidden:animated:))&&
         mlnbt_exchangeInstanceMethod(self, @selector(_startCustomTransition:), @selector(_mlnbt_startCustomTransition:));
+        if (!valid) {
+            NSLog(@"UINavigationController (MLNavigationBarTransition) is not valid now! Please check it.");
+        }
         NSAssert(valid, @"UINavigationController (MLNavigationBarTransition) is not valid now! Please check it.");
 #pragma clang diagnostic pop
     });
@@ -118,6 +121,9 @@ + (void)load {
 
         BOOL valid = mlnbt_exchangeInstanceMethod(cls,@selector(animateTransition:),@selector(_mlnbt_animateTransition:))&&
         mlnbt_exchangeInstanceMethod(cls,@selector(animationEnded:),@selector(_mlnbt_animationEnded:));
+        if (!valid) {
+            NSLog(@"NSObject(MLNavigationBarTransition) is not valid now! Please check it.");
+        }
         NSAssert(valid, @"NSObject(MLNavigationBarTransition) is not valid now! Please check it.");
     });
 }

MLNavigationBarTransition.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
 s.name         = "MLNavigationBarTransition"
-s.version      = "0.0.1"
+s.version      = "0.0.2"
 s.summary      = "Advanced navigation bar transition based on official push-pop transition"
 
 s.homepage     = 'https://github.com/molon/MLNavigationBarTransition'