chore(v2): copy v1 code to v2 folder

[Bobgy]

Changes:

• copy v1 code (current master branch at the time of creating the PR) to v2 folder
• update import path

[wlynch]

General question before I start reviewing these PRs in more details - are the changes to csv/check changes introducing any changes w.r.t input/outputs of the commands, or is this strictly an upgrade using module info?

If there isn't anything that would break compatibility with existing clients, it might make sense to just merge these into v1. 👀
The bits I was primarily concerned with the original v2 proposal were the new commands and the different output format.

[Bobgy]

The PR is no longer necessary, because we decided to use the major branch approach for reaching v2.
#70 (comment)