Package removed from CRAN

[danheck]

The package was removed from CRAN due to a dependency on limSolve. The resubmission to CRAN is not urgent from my view.

@mariusbarth fixed this issue, and I fixed other issues with dplyr::select.

@singmann can you re-run the checks? There may still be some issues with the tests.

[singmann]

Package is back on CRAN

[danheck]

Great, thanks!