fix: Remove deprecated node.js version

Author: Romakita

.travis.yml

@@ -5,13 +5,11 @@ os:
 language: node_js
 node_js:
   - node
-  - '8'
-  - '7'
-  - '6'
-  - '5'
-  - '4'
-  - '0.12'
-  - '0.10'
+  - '15'
+  - '14'
+  - '13'
+  - '12'
+  - '10'
 matrix:
   allow_failures: []
   fast_finish: true