code: function getToken(stripeCredentials) {
      return new Promise(function (resolve, reject) {
  
          var required = [
              "stripe_secret",
              "credit_card_number",
              "credit_card_cvc",
              "credit_card_expiry_month",
              "credit_card_expiry_year"
          ];
  
          if (stripeCredentials.stripe_api_key.indexOf("sk") === 0) {
              console.log("*** WARNING: using a secret stripe api key. ***");
          }
  
          var stripe = require('stripe')(stripeCredentials.stripe_api_key);
  
          var card = {
              number: stripeCredentials.credit_card_number,
              exp_month: stripeCredentials.credit_card_expiry_month,
              exp_year: stripeCredentials.credit_card_expiry_year,
              cvc: stripeCredentials.credit_card_cvc
          };
  
          stripe.tokens.create({ card: card },
              (err, token) => {
                  if (err) {
                      reject(err);
                  } else {
                      resolve(token.id);
                  }
              }
          );
      });
  }
docs: helper function to get a stripe token