Update CHANGELOG.md

Author: lordthorzonus

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Updating from 1.0.0 to 2.0.0
  - Overall php version requirement was bumped from `5.5` to `7.3`
+ - ReactPHP dependencies have been upped to their latest versions
  - Fluent interfaces in `Dataloader::prime()`,`DataLoader::clear` and `DataLoader::clearAll()` were removed. So change usages like:
     ```php
     $dataloader->clear('A')->prime('A', 'Y');
@@ -11,4 +12,4 @@
     $dataloader->clear('A');
     $dataloader->prime('A', 'Y');
     ```
- - All classes in the library have been marked as final.
+ - All classes in the library have been marked as final.