NEW: Wrap lamino operator in Pytorch module

[carterbox]

Purpose

Allow integrating Laminography operator into Pytorch framework

Approach

Wrap the tike cupy operators in the Pytorch API. This is pretty easy because of pytorch/cupy interop.

Pre-Merge Checklists

Submitter

• Write a helpfully descriptive pull request title.
• Organize changes into logically grouped commits with descriptive commit messages.
• Document all new functions.
• Write tests for new functions or explain why they are not needed.
• Build the documentation successfully
• Use yapf to format python code.

Reviewer

• Actually read all of the code.
• Run the new code yourself.
• Write a summary of the changes as you understand them.
• Thank the submitter.