Replaces ~3.* with ~3.0 in Composer

Ref: https://github.com/loadsys/CakePHP-ConfigReadShell/pull/9/files#r27804659
Signed-off-by: Justin Yost <justin.yost@yostivanich.com>

Author: justinyost

README.md

@@ -21,7 +21,7 @@ A CakePHP plugin that provides a Shell to read an app's Configure vars from the
 ## Installation
 
 ```bash
-$ composer require loadsys/config-read:~3.*
+$ composer require loadsys/config-read:~3.0
 ```