Update in viewport to use one IO per viewport

package.json

@@ -27,10 +27,9 @@
   },
   "dependencies": {
     "ember-cli-babel": "^6.6.0",
-    "ember-in-viewport": "~3.0.3"
+    "ember-in-viewport": "DockYard/ember-in-viewport#enhancement/sn/one-io"
   },
   "devDependencies": {
-    "@ember/test-helpers": "^0.7.18",
     "broccoli-asset-rev": "^2.7.0",
     "ember-cli": "~3.2.0",
     "ember-cli-dependency-checker": "^2.0.0",

tests/acceptance/infinity-route-test.js

@@ -106,10 +106,10 @@ module('Acceptance: Infinity Route - infinity routes', function(hooks) {
     await visit('/test-scrollable?perPage=3');
 
     await waitUntil(() => {
-      return postList().querySelectorAll('li').length === 12;
+      return postList().querySelectorAll('li').length === 15;
     });
 
-    shouldBeItemsOnTheList(assert, 12);
+    shouldBeItemsOnTheList(assert, 15);
   });
 
   module('Acceptance: Infinity Route - multiple pages fetched', function(/*hooks*/) {
@@ -125,10 +125,10 @@ module('Acceptance: Infinity Route - infinity routes', function(hooks) {
       document.getElementsByClassName('infinity-loader-above')[0].scrollIntoView(false);
 
       await waitUntil(() => {
-        return postList().querySelectorAll('li').length === 75;
+        return postList().querySelectorAll('li').length === 50;
       });
 
-      shouldBeItemsOnTheList(assert, 75);
+      shouldBeItemsOnTheList(assert, 50);
     });
   });
 

tests/unit/mixins/route-test.js

@@ -208,7 +208,7 @@ module('Unit | RouteMixin', function(hooks) {
       this.callModelHook(route);
     });
 
-    test('scott It allows to set startingPage as 0', function(assert) {
+    test('It allows to set startingPage as 0', function(assert) {
       let store = this.createMockStore( this.EA([{id: 1, name: 'Test'}], { total_pages: 1 }) );
       let route = this.createRoute(
         ['item', {