Build Tools: Switch to Node 10.13.0.

Now that Node 10 is the LTS branch, with 10.13.0 as the first LTS release, let's use that for building WordPress.

Merges [43853] from the 5.0 branch to trunk.

Props pento.
See #45241.


git-svn-id: https://develop.svn.wordpress.org/trunk@44219 602fd350-edb4-49c9-b593-d223f7449a82

.travis.yml

@@ -93,7 +93,7 @@ before_script:
   fi
 - npm --version
 - node --version
-- nvm install 8.9.3
+- nvm install 10.13.0
 - npm install -g grunt-cli
 - npm install
 - npm prune

package.json

@@ -7,7 +7,7 @@
 		"url": "https://develop.svn.wordpress.org/trunk"
 	},
 	"engines": {
-		"node": "8.9.3",
+		"node": "10.13.0",
 		"npm": "6.1.0"
 	},
 	"author": "The WordPress Contributors",