Question: Can anyone please tell me how can I add a new column of type enum to my schema in order to implement a Doctrine Migration?

Answer: 
Modify your schema and don't build yet the model. run doctrine schema diff then a migration class will be generated for you. Finally you can rebuild your models/forms/filters
```
Model:  
  column:  
    type: enum  
    values: [one, two, three]  

(optional:)  
    notnull: false  
    default: one #or two or three  

```