aspect ratio of posters in carousel

Before changing built-in FM aspect ratio for carousel: 
![image](https://user-images.githubusercontent.com/39224115/75617896-49edc380-5b33-11ea-90b3-0a06ab7cc100.png)


After:
![image](https://user-images.githubusercontent.com/39224115/75617908-743f8100-5b33-11ea-8a7f-0e8a7abe7c69.png)
