Adding sudo option to `enter` command.
Adding sudo option to `enter` command.

Example:

$ enter sudo id
Running 'id' as root inside container
uid=0(root) gid=0(root) groups=0(root)

davenuman/bowline,Pythagory/bowline,lopezs/bowline,ducdebreme/bowline,lopezs/bowline,davenuman/bowline,davenuman/bowline,openprivacy/bowline,ducdebreme/bowline,openprivacy/bowline,Pythagory/bowline,ducdebreme/bowline,Pythagory/bowline,lopezs/bowline,openprivacy/bowline