Turn Dockerfile to `{dockerfiler}` object

[ColinFay]

It would ne nice to be able to read a Dockerfile and manipulate it

[JosiahParry]

Giving this a +1 would like this functionality

[michkam89]

giving +1 to this as well :)

[ColinFay]

Note to self: i think this can be pretty straightforward to implement as long as we don't check for the validity of the Dockerfile and assume the user inputs a valid one

[JosiahParry]

Any progress on this here fella?

[VincentGuyader]

done