Method userHasRedeemed

app/models/Prepaid.js:38–43

(userID)

    }

    userHasRedeemed (userID) {
      for (const redeemer of Array.from(this.get('redeemers'))) {
        if (redeemer.userID === userID) { return redeemer.date }
      }
      return null
    }

    initialize () {
      this.listenTo(this, 'add', function () {