remove r-base version selectors

[rvalieris]

the presence of the version selectors on the r-base package prevents conda from generating pinned packages.

https://anaconda.org/conda-forge/r-permute/files

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[rvalieris]

anybody knows why circleci is not running here ?
https://circleci.com/gh/conda-forge/r-permute-feedstock/tree/pull/1

Your build was not run - reason code (:no-followers).
We did not test this push because nobody is following the project

[bgruening]

@conda-forge-admin, please update circle

[bgruening]

@conda-forge-admin, please rerender

[jdblischak]

I vote for merging this. The CircleCI builds will likely be triggered upon merging.

[jdblischak]

Well I was wrong. :-( The CircleCI builds weren't triggered. CircleCI did not build them because:

We did not test this push because nobody is following the project

https://circleci.com/gh/conda-forge/r-permute-feedstock/18
https://circleci.com/gh/conda-forge/r-permute-feedstock/19

I did a little bit of searching, but wasn't able to find any obvious solution to this.