Modernize to hubot 14 (ESM)

- ESM ("type": "module"); hubot 14.1.0
- deps: hubot-xmpp (kosmos/hubot-xmpp@master), hubot-help ^2.1.5, hubot-rules
  ^2.1.1, hubot-redis-brain 3.0.1, hubot-incoming-webhook ^2.0.0,
  @kredits/hubot-kredits (git master)
- drop hubot-irc, coffee-script, request, hubot-auth, hubot-scripts,
  hubot-shipit, hubot-tell, hubot-seen, hubot-schedule, cheerio, node-fetch
- external-scripts.json: hubot-help, hubot-redis-brain, hubot-rules,
  hubot-incoming-webhook, @kredits/hubot-kredits
- scripts/health.js -> ESM; run.sh -> -a hubot-xmpp
- drop stale .jshintrc

scripts/health.js

@@ -1,5 +1,11 @@
-module.exports = function (robot) {
+// Description:
+//   Liveness/health endpoint for the HTTP server.
+//
+// Commands:
+//   None
+
+export default function (robot) {
   robot.router.get('/health/live', (req, res) => {
-    res.send('OK');
-  });
+    res.send('OK')
+  })
 }