refactor: schema modularization

lib/new-admin/graphql/resolvers/promo.resolver.js

@@ -0,0 +1,13 @@
+const promoCodeManager = require('../../../promo-codes')
+
+const resolvers = {
+  Query: {
+    promoCodes: () => promoCodeManager.getAvailablePromoCodes()
+  },
+  Mutation: {
+    createPromoCode: (...[, { code, discount }]) => promoCodeManager.createPromoCode(code, discount),
+    deletePromoCode: (...[, { codeId }]) => promoCodeManager.deletePromoCode(codeId)
+  }
+}
+
+module.exports = resolvers