gnu: Add r-ggdendro.

* gnu/packages/statistics.scm (r-ggdendro): New variable.

Merge branch 'master' into staging

gnu: r-lme4: Update to 1.1-14.

* gnu/packages/statistics.scm (r-lme4): Update to 1.1-14.

gnu: r-doparallel: Update to 1.0.11.

* gnu/packages/statistics.scm (r-doparallel): Update to 1.0.11.

gnu: r-checkmate: Update to 1.8.4.

* gnu/packages/statistics.scm (r-checkmate): Update to 1.8.4.

gnu: r-backports: Update to 1.1.1.

* gnu/packages/statistics.scm (r-backports): Update to 1.1.1.

gnu: r-minimal: Update to 3.4.2.

* gnu/packages/statistics.scm (r-minimal): Update to 3.4.2.

Merge branch 'master' into staging

gnu: r-glmnet: Update to 2.0-13.

* gnu/packages/statistics.scm (r-glmnet): Update to 2.0-13.

gnu: r-segmented: Update to 0.5-2.2.

* gnu/packages/statistics.scm (r-segmented): Update to 0.5-2.2.

gnu: r-mgcv: Update to 1.8-22.

* gnu/packages/statistics.scm (r-mgcv): Update to 1.8-22.

Merge branch 'master' into staging

gnu: r-glmnet: Update to 2.0-12.

* gnu/packages/statistics.scm (r-glmnet): Update to 2.0-12.

gnu: r-lambda-r: Update to 1.2.

* gnu/packages/statistics.scm (r-lambda-r): Update to 1.2.

gnu: r-gridextra: Update to 2.3.

* gnu/packages/statistics.scm (r-gridextra): Update to 2.3.

gnu: r-dplyr: Update to 0.7.3.

* gnu/packages/statistics.scm (r-dplyr): Update to 0.7.3.

gnu: r-crayon: Update to 1.3.4.

* gnu/packages/statistics.scm (r-crayon): Update to 1.3.4.

gnu: r-svglite: Update to 1.2.1.

* gnu/packages/statistics.scm (r-svglite): Update to 1.2.1.

gnu: r-mgcv: Update to 1.8-21.

* gnu/packages/statistics.scm (r-mgcv): Update to 1.8-21.

gnu: r-caret: Update to 6.0-77.

* gnu/packages/statistics.scm (r-caret): Update to 6.0-77.
[propagated-inputs]: Remove r-car; add r-recipes and r-withr.