Fix for app installer sending array instead of string.

Issue discovered when trying to install the stripe app on a fresh master copy of elefantCMS. 

Error:  
![issue](https://cloud.githubusercontent.com/assets/1837484/3505423/5a8f8eb0-065e-11e4-958a-1a6e0e401c54.png)

Solved by adding the `['name']` array parameter.