update example transition classes

examples/firebase/style.css

@@ -19,7 +19,7 @@ ul {
   border-bottom: 1px solid #eee;
 }
 
-.v-enter, .v-leave-active {
+.v-enter, .v-leave-to {
   height: 0;
   padding-top: 0;
   padding-bottom: 0;

examples/modal/style.css

@@ -52,12 +52,12 @@
   opacity: 0;
 }
 
-.modal-leave-active {
+.modal-leave-to {
   opacity: 0;
 }
 
 .modal-enter .modal-container,
-.modal-leave-active .modal-container {
+.modal-leave-to .modal-container {
   -webkit-transform: scale(1.1);
   transform: scale(1.1);
 }