chore: change supported node versions

This adds testing for node v11 - v15. This removes testing for node v6
and v7 because codecov breaks on these versions. The nodejs org
currently supports [10, 12, 14, 15].

This adds a small logging statement to the check-node-support script.

Test: npm run check-node-support

.travis.yml

@@ -1,11 +1,14 @@
 language: node_js
 sudo: false
 node_js:
-  - 6
-  - 7
   - 8
   - 9
   - 10
+  - 11
+  - 12
+  - 13
+  - 14
+  - 15
 
 os:
   - linux

README.md

@@ -10,7 +10,7 @@
 commands, providing an easy solution for simple Unix-like, cross-platform
 commands in npm package scripts.
 
-`shx` is proudly tested on every node release since <!-- start minVersion -->`v6`<!-- stop minVersion -->!
+`shx` is proudly tested on every node release since <!-- start minVersion -->`v8`<!-- stop minVersion -->!
 
 ## Difference Between ShellJS and shx
 

appveyor.yml

@@ -1,10 +1,13 @@
 environment:
   matrix:
+    - nodejs_version: '15'
+    - nodejs_version: '14'
+    - nodejs_version: '13'
+    - nodejs_version: '12'
+    - nodejs_version: '11'
     - nodejs_version: '10'
     - nodejs_version: '9'
     - nodejs_version: '8'
-    - nodejs_version: '7'
-    - nodejs_version: '6'
 
 version: '{build}'
 

package.json

@@ -75,6 +75,6 @@
     "shelljs": "^0.8.4"
   },
   "engines": {
-    "node": ">=6"
+    "node": ">=8"
   }
 }

scripts/check-node-support.js

@@ -8,8 +8,8 @@ var yaml = require('js-yaml');
 var shell = require('shelljs');
 
 // This is the authoritative list of supported node versions.
-var MIN_NODE_VERSION = 6;
-var MAX_NODE_VERSION = 10;
+var MIN_NODE_VERSION = 8;
+var MAX_NODE_VERSION = 15;
 
 function checkReadme(minNodeVersion) {
   var start = '<!-- start minVersion -->';
@@ -78,6 +78,8 @@ try {
   var appveyorFileName = path.join(__dirname, '..', 'appveyor.yml');
   var appveyorYaml = yaml.safeLoad(shell.cat(appveyorFileName));
   checkAppveyor(MIN_NODE_VERSION, MAX_NODE_VERSION, appveyorYaml);
+  console.log('All files look good (this project supports v' +
+      MIN_NODE_VERSION + '-v' + MAX_NODE_VERSION + ')!');
 } catch (e) {
   console.error('Please check the files which declare our Node version');
   console.error('support, as something is out-of-sync. This script failed');