Merge pull request #5 from explore-node-js/eugene-matvejev-patch-2

update README.md

Author: eugene-matvejev

README.md

@@ -6,7 +6,7 @@ abstract and easy way how to work with bytes in JS
  * npm v3+
 
 ## used technologies
- * jest
+ * jest _[for tests only]_
 
 ## how to execute tests
  `npm test`