Feat: refactor routes.js express entrypoint config

Feat: express config script refactor

Feat: add state and settingsCache files

lib/middlewares/errorHandler.js

@@ -0,0 +1,15 @@
+const logger = require('../logger')
+
+function errorHandler (err, req, res, next) {
+  const statusCode = err.name === 'HTTPError'
+    ? err.code || 500
+    : 500
+
+  const json = { error: err.message }
+
+  if (statusCode >= 400) logger.error(err)
+
+  return res.status(statusCode).json(json)
+}
+
+module.exports = errorHandler