Travis CI: Another attempt to fix things

Seems that I don't understand YAML
2020-02-04 15:25:34 +00:00 · 2020-02-04 15:25:34 +00:00 · 33087ccee9
commit 33087ccee9
--- a/.travis.yml
+++ b/.travis.yml
@ -1,5 +1,6 @@
 language: node_js
-  - 12
+node_js:
+  - "12.4.0"

 stages:
  - name: test