fix snackbar persistance, update dependancies

example/lib/main.dart

@@ -116,6 +116,21 @@ class _ExampleMihPackageState extends State<ExampleMihPackage> {
               buttonColor: MihColors.green(),
               child: Text("Press"),
             ),
+            MihButton(
+              width: 300,
+              onPressed: () {
+                ScaffoldMessenger.of(context).showSnackBar(
+                  MihSnackBar(
+                    child: Text("Tester"),
+                    duration: 2,
+                    backgroundColor: MihColors.secondary(),
+                    closeIconColor: MihColors.red(),
+                  ),
+                );
+              },
+              buttonColor: MihColors.green(),
+              child: Text("Snack Test"),
+            ),
           ],
         ),
       ),