message: Expose total user count in Prometheus metrics
  (including admin and accounting users)
diff: @@ -82,14 +82,14 @@ exports.observeMetrics = function observeMetrics () {
  orderMetrics.set(orders)
  })
  - userTotalMetrics.set(0)
  models.User.count({ where: { role: { [Op.eq]: ['customer'] } } }).then(count => {
  userMetrics.set({ type: 'standard' }, count)
  - if (count > 0) userTotalMetrics.inc(count)
  })
  models.User.count({ where: { role: { [Op.eq]: 'deluxe' } } }).then(count => {
  userMetrics.set({ type: 'deluxe' }, count)
  - if (count > 0) userTotalMetrics.inc(count)
  + })
  + models.User.count().then(count => {
  + userTotalMetrics.set(count)
  })
  models.Wallet.sum('balance').then(totalBalance => {
  