Update Travis node version

Author: HiDeoo

.travis.yml

@@ -1,15 +1,14 @@
 language: node_js
 node_js:
-  - 7
-  - 8
+  - 10
 notifications:
   email:
     on_success: never
 script:
-  - npm run lint
-  - npm run test
+  - yarn run lint
+  - yarn run test
 cache:
   directories:
     - node_modules
 after_success:
-  - npm run coveralls
+  - yarn run coveralls