Pin Travis to Node 10.15.3 to closely match the bundled version

Author: pimterry

.travis.yml

@@ -3,7 +3,7 @@ sudo: required
 language: node_js
 node_js:
 - node
-- '10'
+- '10.15.3'
 - '8'
 before_install:
 - sudo apt-get install p7zip-full xterm
@@ -25,7 +25,7 @@ addons:
 jobs:
   include:
     - stage: Release prebuilt binaries
-      node_js: '10'
+      node_js: '10.15.3'
       echo: 'Deploying prebuilt binaries...'
       script: npm run build
       before_deploy: