Parameterized Ink Sample Vial Flange

I have some ink sample vials from Goulet Pens and keep spilling them when I go to refill my pen. I like the flange-style holder that Lundy created, but it's specific to a sample vial with a different diameter than the ones I got, so I recreated it in OpenSCAD and made it customizable.

* The "vial_diameter" parameter is actually the INNER DIAMETER of the flange, rather than the OUTER DIAMETER of the vial. Print a test-fit to make sure you've got that right.
* The "flange_diameter" parameter determines how big the actual flange is.
* The "flange_height" parameter determines how tall the flange is, overall (the vial sits 1mm above the bottom of the flange)
* The "wall_thickness" parameter defines the difference between the OD and the ID of the very top of the flange. I think playing with this will help alleviate that roughness seen at the very top of the flange in my cover photo.