Adds flexible from the {flexsurv} package to {mlr3}.
Install the latest release of the package via
install.packages("mlr3learners.flexsurv")by following the instructions in the mlr3learners.drat README.
Alternatively, you can install the latest version of {mlr3learners.flexsurv} from Github with:
remotes::install_github("mlr3learners/mlr3learners.flexsurv")