chore(nodejs): add support for version 10

Author: Alexandre-io

.travis.yml

@@ -1,10 +1,8 @@
 language: node_js
 node_js:
+  - '10'
+  - '9'
+  - '8'
   - '7'
   - '6'
-  - '5'
-  - '4'
-  - '3'
-  - '2'
-  - '0.12'
 script: npm install . && npm test