Add version constraints.

Author: yajra

installation.md

@@ -23,7 +23,7 @@ Laravel Datatables can be installed with [Composer](http://getcomposer.org/doc/0
 Run the following command in your project to get the latest version of the package:
 
 ```
-composer require yajra/laravel-datatables-oracle
+composer require yajra/laravel-datatables-oracle:^7.0
 ```
 
 <a name="configuration"></a>

upgrade.md

@@ -2,8 +2,8 @@
 
 <a name="v6-to-v7"></a>
 ## Upgrading from v6.x to v7.x
-  - composer require yajra/laravel-datatables-oracle
-  - composer require yajra/laravel-datatables-buttons
+  - composer require yajra/laravel-datatables-oracle:^7.0
+  - composer require yajra/laravel-datatables-buttons:^1.0
   - php artisan vendor:publish --tag=datatables --force
   - php artisan vendor:publish --tag=datatables-buttons --force