ci(node versions): change running node verison the same as karma package

Author: elpddev

.travis.yml

@@ -1,9 +1,8 @@
 sudo: false
 language: node_js
 node_js:
-  - stable
-  - 4
-  - '0.10'
+  - 8
+  - 10
 
 before_install:
   - npm install -g npm