chore(ci): MacOS NodeJS 14.1.0 Puppeteer NPM install issue, updated T…

…ravis conf to LTS see puppeteer/puppeteer#5719 (comment) also see https://travis-ci.org/github/daisy/ace-gui/jobs/681399699

.travis.yml

@@ -21,30 +21,30 @@ matrix:
       os: osx
       osx_image: xcode11.2
       language: node_js
-      node_js: "node"
+      node_js: "lts/*"
       env:
         - ELECTRON_CACHE=$HOME/.cache/electron
         - ELECTRON_BUILDER_CACHE=$HOME/.cache/electron-builder
 #if: type = push OR pull_request
     - os: linux
       language: node_js
-      node_js: "node"
+      node_js: "lts/*"
       env:
         - ELECTRON_CACHE=$HOME/.cache/electron
         - ELECTRON_BUILDER_CACHE=$HOME/.cache/electron-builder
     - if: type = push
       os: linux
       services: docker
       language: node_js
-      node_js: "node"
+      node_js: "lts/*"
       env:
         - TRAVIS_OS_NAME_=windows
 # https://www.electron.build/multi-platform-build
 # Switch to TravisCI "native" Windows support when it is ready (the main blocking issue right now is secret ENV vars, which we need to deploy to GitHub)
 # https://travis-ci.community/c/environments/windows
 # - os: windows
 #   language: node_js
-#   node_js: "node"
+#   node_js: "lts/*"
 #   env:
 #     - ELECTRON_CACHE=$HOME/.cache/electron
 #     - ELECTRON_BUILDER_CACHE=$HOME/.cache/electron-builder