feat(util): use transition-end from npm

addon/components/modal.js

@@ -3,7 +3,8 @@ import Component from '@ember/component';
 import RSVP from 'rsvp';
 import { camelize } from '@ember/string';
 import { computed } from '@ember/object';
-import { hasTransitions, onTransitionEnd } from 'ember-modal-service/utils/css-transitions';
+import onTransitionEnd from 'ember-transition-end/utils/on-transition-end';
+import { hasTransitions } from 'ember-modal-service/utils/css-transitions';
 import { inject as service } from '@ember/service';
 import { on } from '@ember/object/evented';
 import { run } from '@ember/runloop';

addon/utils/css-transitions/index.js

@@ -1,7 +1,5 @@
-import onTransitionEnd from './on-transition-end';
 import hasTransitions from './has-transitions';
 
 export {
-	onTransitionEnd,
 	hasTransitions
 };

package.json

@@ -46,6 +46,7 @@
   "scripts": {
     "build": "ember build",
     "check-coverage": "istanbul check-coverage coverage/coverage-final.json --statements 85 --functions 85 --branches 85 --lines 85",
+    "commit": "git-cz",
     "lint": "npm run lint:js && npm run lint:hbs",
     "lint:hbs": "ember-template-lint .",
     "lint:js": "eslint --max-warnings 0 ./*.js addon app config tests",
@@ -60,7 +61,8 @@
   "dependencies": {
     "ember-cli-babel": "^7.4.3",
     "ember-cli-htmlbars": "^3.0.0",
-    "ember-task-scheduler": "^1.0.2"
+    "ember-task-scheduler": "^1.0.2",
+    "ember-transition-end": "^1.0.0"
   },
   "devDependencies": {
     "@commitlint/cli": "^7.6.0",

tests/unit/components/modal-test.js

@@ -5,7 +5,7 @@ import sinon from 'sinon';
 import waitFor from 'ember-task-scheduler/utils/wait-for';
 import { A } from '@ember/array';
 import { moduleForComponent, test } from 'ember-qunit';
-import { onTransitionEnd } from 'ember-modal-service/utils/css-transitions';
+import onTransitionEnd from 'ember-transition-end/utils/on-transition-end';
 import { run } from '@ember/runloop';
 
 const { spy } = sinon;