Updated readme [skip ci]

Author: ankane

README.md

@@ -280,12 +280,6 @@ Get an array
 $arr = $vec->toArray();
 ```
 
-## Upgrading
-
-### 0.1.4
-
-The package name was changed from `ankane/pgvector` to `pgvector/pgvector`. Update it in `composer.json` to remove the message.
-
 ## History
 
 View the [changelog](https://github.com/pgvector/pgvector-php/blob/master/CHANGELOG.md)