Add contributor and kredits count to page

app/controllers/index.js

@@ -0,0 +1,20 @@
+import Ember from 'ember';
+
+const {
+  computed
+} = Ember;
+
+export default Ember.Controller.extend({
+
+  contributorsCount: computed('model.contributors.[]', function() {
+    return this.get('model.contributors').length;
+  }),
+
+  kreditsSum: computed('model.contributors.[]', function() {
+    let kredits = this.get('model.contributors').mapBy('kredits');
+    return kredits.reduce(function(previousValue, currentValue) {
+      return currentValue + previousValue;
+    });
+  })
+
+});