The code should actually read:
myApp = angular.module('myApp', ['ngRoute']);
You have tried to call angular as a function which is why you are getting that error!
An example
I went so far as to create an angular page based on your grunt minified file (downloaded from the link). Everything worked well.
HTML
<html ng-app="app">
<body ng-controller="test">
{{test}}
<script src="angular-gruntmin.js" type="text/javascript"></script>
<script src="test.js" type="text/javascript"></script>
</body>
</html>
Javascript
var app = angular.module('app', []);
app.controller('test', function ($scope) {
$scope.test = "ABCDEFG";
});
You can see that in a plunker here: http://plnkr.co/edit/0fX0wwulbWBS8Plbmarl?p=preview