fix: update CI config

Author: alexlafroscia

.travis.yml

@@ -3,7 +3,7 @@ language: node_js
 node_js:
   # we recommend testing addons with the same minimum supported node version as Ember CLI
   # so that your addon works for all apps
-  - "4"
+  - "6"
 
 sudo: false
 dist: trusty
@@ -35,11 +35,6 @@ matrix:
   allow_failures:
     - env: EMBER_TRY_SCENARIO=ember-canary
 
-before_install:
-  - npm config set spin false
-  - npm install -g npm@4
-  - npm --version
-
 script:
   - npm run lint:js
   # Usually, it's ok to finish the test scenario without reverting

config/ember-try.js

@@ -1,65 +1,66 @@
-'use strict';
+"use strict";
 
-const getChannelURL = require('ember-source-channel-url');
+const getChannelURL = require("ember-source-channel-url");
 
 module.exports = function() {
   return Promise.all([
-    getChannelURL('release'),
-    getChannelURL('beta'),
-    getChannelURL('canary'),
-  ]).then((urls) => {
+    getChannelURL("release"),
+    getChannelURL("beta"),
+    getChannelURL("canary")
+  ]).then(urls => {
     return {
+      useYarn: true,
       scenarios: [
         {
-          name: 'ember-lts-2.12',
+          name: "ember-lts-2.12",
           npm: {
             devDependencies: {
-              'ember-source': '~2.12.0'
+              "ember-source": "~2.12.0"
             }
           }
         },
         {
-          name: 'ember-lts-2.16',
+          name: "ember-lts-2.16",
           npm: {
             devDependencies: {
-              'ember-source': '~2.16.0'
+              "ember-source": "~2.16.0"
             }
           }
         },
         {
-          name: 'ember-lts-2.18',
+          name: "ember-lts-2.18",
           npm: {
             devDependencies: {
-              'ember-source': '~2.18.0'
+              "ember-source": "~2.18.0"
             }
           }
         },
         {
-          name: 'ember-release',
+          name: "ember-release",
           npm: {
             devDependencies: {
-              'ember-source': urls[0]
+              "ember-source": urls[0]
             }
           }
         },
         {
-          name: 'ember-beta',
+          name: "ember-beta",
           npm: {
             devDependencies: {
-              'ember-source': urls[1]
+              "ember-source": urls[1]
             }
           }
         },
         {
-          name: 'ember-canary',
+          name: "ember-canary",
           npm: {
             devDependencies: {
-              'ember-source': urls[2]
+              "ember-source": urls[2]
             }
           }
         },
         {
-          name: 'ember-default',
+          name: "ember-default",
           npm: {
             devDependencies: {}
           }