(experiment) Lock Node v12.14.1

.travis.yml

@@ -12,10 +12,10 @@ matrix:
       sudo: required
       env: BUILDARCH=arm
       dist: trusty
-#   - os: osx
+    - os: osx
 
 language: node_js
-node_js: "12"
+node_js: "12.14.1"
 
 before_install:
   - curl -o- -L https://yarnpkg.com/install.sh | bash