Corrected the repository to install

Sorry @andrejsstepanovs but I did not understand your comment.
The project "https://github.com/nuxia/BusinessDayManipulator" is not mine! 
I only help the two projects "nuxia/BusinessDayManipulator" and "andrejsstepanovs/business-days-calculator" with my PR to install via command line in composer. I corrected you PR, thanks for the review.
Regards

README.md

@@ -11,7 +11,7 @@ Business Days Calculator
 * If you're using Composer to manage dependencies, you can use
 
 ```sh
-composer require nuxia/business-day-manipulator
+composer require andrejsstepanovs/business-days-calculator
 ```
 
 or add to your composer.json file: