Fixed successful creation message

`virtphp create --install-path="/some/where" envname` outputs `You can activate your new environment using: ~$ source /some/where/bin/activate` instead of `ou can activate your new environment using: ~$ source /some/where/envname/bin/activate`

![screen shot 2014-05-22 at 15 44 30](https://cloud.githubusercontent.com/assets/1788218/3054426/46f1c754-e1b7-11e3-9174-7c8339690ffc.png)