Try using node 8 lts instead of latest one

yamalight · yamalight · commit 3f8e6f443cdd · 2017-11-30T13:34:36.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 
-node_js: node
+node_js: 8
 
 cache: yarn
 
