Fix(#54): Dependency on R update

[andybeet]

Justification

Code uses native pipe, need R >= 4.1 for its use

Fixes #54

Types of changes

What types of changes does this pull request introduce? Put an x in the boxes that apply.
This will inform the new release number.

• Fix (non-breaking change which fixes a bug)
• Feature (non-breaking change which adds or changes functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other change (if none of the other choices apply)

Further comments

If this is a relatively large or complex change, kick off a discussion by explaining why you chose the solution you did, what alternatives you considered, problems you may have encountered, etc.

Reviewer instructions

Nothing specific. The air checks will fail. This is addressed in PR #57

Formatting

This repo contains an air.toml file that automatically formats code to a set of standards.
It is preferred that contributors and reviewers install the Air formatting tool.
Code submitted in this pull request will be automatically checked for correct formatting.