fix(discount-code-importer): improve error logging (#1833)

Co-authored-by: Vineet Kumar <javascripter.pune@outlook.com>

Author: VineetKumarKushwaha

.changeset/two-timers-flash.md

@@ -0,0 +1,5 @@
+---
+'@commercetools/discount-code-importer': patch
+---
+
+Improve Error Logging for Discount Importer

packages/discount-code-importer/src/main.js

@@ -146,13 +146,14 @@ export default class DiscountCodeImport {
       .then((): Promise<void> => Promise.resolve())
       .catch(
         // eslint-disable-next-line
-        (caughtError): Object =>
-          new DiscountCodeImportError(
+        (caughtError): Object => {
+          this.logger.error(caughtError.message || caughtError)
+          return new DiscountCodeImportError(
             'Processing batches failed',
             caughtError.message || caughtError,
             this._summary
-          )
-      )
+          );
+        })
   }
 
   _createOrUpdate(