build!: drops Node 6 and 4. begin following Node.js LTS schedule

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 node_modules
 .nyc_output
+package-lock.json

.nvmrc

@@ -0,0 +1 @@
+lts/*

.travis.yml

@@ -1,7 +1,9 @@
 language: node_js
 sudo: false
 node_js:
-  - "4"
-  - "6"
+  - "10"
+  - "12"
+  - "14"
+  - "lts/*"
   - "node"
 after_success: npm run coverage

README.md

@@ -95,6 +95,12 @@ What locale is currently being used?
 
 Update the current locale with the key value pairs in `obj`.
 
+## Supported Node.js Versions
+
+Libraries in this ecosystem make a best effort to track
+[Node.js' release schedule](https://nodejs.org/en/about/releases/). Here's [a
+post on why we think this is important](https://medium.com/the-node-js-collection/maintainers-should-consider-following-node-js-release-schedule-ab08ed4de71a).
+
 ## License
 
 ISC

package.json

@@ -2,31 +2,31 @@
   "name": "y18n",
   "version": "4.0.0",
   "description": "the bare-bones internationalization library used by yargs",
-  "main": "index.js",
-  "scripts": {
-    "pretest": "standard",
-    "test": "nyc mocha",
-    "coverage": "nyc report --reporter=text-lcov | coveralls",
-    "release": "standard-version"
+  "keywords": [
+    "i18n",
+    "internationalization",
+    "yargs"
+  ],
+  "homepage": "https://github.com/yargs/y18n",
+  "bugs": {
+    "url": "https://github.com/yargs/y18n/issues"
   },
   "repository": {
     "type": "git",
     "url": "git@github.com:yargs/y18n.git"
   },
+  "license": "ISC",
+  "author": "Ben Coe <ben@npmjs.com>",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
-  "keywords": [
-    "i18n",
-    "internationalization",
-    "yargs"
-  ],
-  "author": "Ben Coe <ben@npmjs.com>",
-  "license": "ISC",
-  "bugs": {
-    "url": "https://github.com/yargs/y18n/issues"
+  "scripts": {
+    "coverage": "nyc report --reporter=text-lcov | coveralls",
+    "release": "standard-version",
+    "pretest": "standard",
+    "test": "nyc mocha"
   },
-  "homepage": "https://github.com/yargs/y18n",
   "devDependencies": {
     "chai": "^4.0.1",
     "coveralls": "^3.0.0",
@@ -35,5 +35,8 @@
     "rimraf": "^2.5.0",
     "standard": "^10.0.0-beta.0",
     "standard-version": "^5.0.0"
+  },
+  "engines": {
+    "node": ">=10"
   }
 }