ember-exam CI has been failing due to dependency issue with ember-cod…

…e-snippet. We are using ember-cli-addon-docs has dependency of ember-code-snippet@^2.4.0 in ember-exam and they released new version (2.4.1) with the changes that make the engine incompatible with node version 6.

.travis.yml

@@ -1,7 +1,7 @@
 ---
 language: node_js
 node_js:
-  - "6"
+  - "8"
 
 addons:
   chrome: stable

package.json

@@ -30,6 +30,7 @@
     "cli-table3": "^0.5.1",
     "debug": "^4.1.0",
     "ember-cli-babel": "^7.8.0",
+    "ember-cli-htmlbars": "^3.0.1",
     "execa": "^1.0.0",
     "fs-extra": "^8.0.1",
     "js-yaml": "^3.13.1",
@@ -40,15 +41,14 @@
   "devDependencies": {
     "@ember/optional-features": "^0.7.0",
     "codeclimate-test-reporter": "^0.5.0",
-    "ember-cli": "~3.9.0",
+    "ember-cli": "^3.10.1",
     "ember-cli-addon-docs": "^0.6.13",
     "ember-cli-addon-docs-yuidoc": "^0.2.1",
     "ember-cli-dependency-checker": "^3.0.0",
     "ember-cli-deploy": "^1.0.2",
     "ember-cli-deploy-build": "^1.1.1",
     "ember-cli-deploy-git": "^1.3.3",
     "ember-cli-deploy-git-ci": "^1.0.1",
-    "ember-cli-htmlbars": "^3.0.1",
     "ember-cli-htmlbars-inline-precompile": "^2.0.0",
     "ember-cli-inject-live-reload": "^2.0.1",
     "ember-cli-shims": "^1.1.0",
@@ -74,7 +74,7 @@
     "testdouble": "^3.12.0"
   },
   "engines": {
-    "node": "^6.14.0 || ^8.10.0 || >= 10.*"
+    "node": "8.* || >= 10.*"
   },
   "ember-addon": {
     "configPath": "tests/dummy/config"