i think the problem is what you should put the cordova.js above ib/ngCordova/dist/ng-cordova.js like this
<script src="lib/ionic/js/ionic.bundle.js"></script>
<script src="lib/ionic-service-core/ionic-core.js"></script>
<script src="lib/ionic-service-push/ionic-push.js"></script>
<script src="lib/ngCordova/dist/ng-cordova.js"></script>
<script src="cordova.js"></script>
Sorry for my bad english