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

external-scripts.json

@@ -1,12 +1,7 @@
 [
   "@kredits/hubot-kredits",
-  "hubot-auth",
   "hubot-help",
-  "hubot-redis-brain",
-  "hubot-rules",
-  "hubot-shipit",
-  "hubot-tell",
-  "hubot-seen",
   "hubot-incoming-webhook",
-  "hubot-schedule"
+  "hubot-redis-brain",
+  "hubot-rules"
 ]