Fix version in readme

[Marcelo Canina]

Following main readme guide I was getting the following error when adding in composer.json with Laravel 4.1: "wardrobe/core": "1.0.*"

 $ composer update
 Loading composer repositories with package information
 Updating dependencies (including require-dev)
 Your requirements could not be resolved to an installable set of packages.

 Problem 1
- wardrobe/core 1.0.0-rc.1 requires laravel/framework 4.0.x -> satisfiable by laravel/framework[4.0.x-dev].
- wardrobe/core 1.0.x-dev requires laravel/framework 4.0.x -> satisfiable by laravel/framework[4.0.x-dev].
- wardrobe/core v1.0.0 requires laravel/framework 4.0.x -> satisfiable by laravel/framework[4.0.x-dev].
- wardrobe/core v1.0.1 requires laravel/framework 4.0.x -> satisfiable by laravel/framework[4.0.x-dev].
- Conclusion: don't install laravel/framework 4.0.x-dev
- Installation request for wardrobe/core 1.0.* -> satisfiable by wardrobe/core[1.0.0-rc.1, 1.0.x-dev, v1.0.0, v1.0.1].

Solved changing version in composer: "wardrobe/core": "1.2.*".
Nice package! Keep it up.