Chris

[chriszhang3]

Checklist

• [x] Added an entry in doc/news/.
• [x] Added a test for this change.

Made changes according to what Vincent and I talked about see open issue #62. Namely I added the to_cylinder_graph function and the Twist class. The twist related code does not quite have the same interface. We can talk about that more if you want to. Also included tests.

[videlec]

@chriszhang3 Note that instead of Twist.twist_dimension you can use CylinderDiagram.homological_dimension_of_cylinders.

[videlec]

@chriszhang3 For me this is ready to go. I changed a bit some names. Tell me if it looks ok for you.

[chriszhang3]

@videlec Looks great!