removed plyr and reshape2

closes #1103

docs/using/selecting.md

@@ -60,9 +60,9 @@ repository. The following sections describe these images including their content
 [tidyr](http://tidyr.tidyverse.org/), [readr](http://readr.tidyverse.org/), [purrr](http://purrr.tidyverse.org/), [tibble](http://tibble.tidyverse.org/),
 [stringr](http://stringr.tidyverse.org/), [lubridate](http://lubridate.tidyverse.org/), and
 [broom](https://cran.r-project.org/web/packages/broom/vignettes/broom.html) from [conda-forge](https://conda-forge.github.io/feedstocks)
-* [plyr](https://cran.r-project.org/web/packages/plyr/index.html), [devtools](https://cran.r-project.org/web/packages/devtools/index.html),
+* [devtools](https://cran.r-project.org/web/packages/devtools/index.html),
 [shiny](https://shiny.rstudio.com/), [rmarkdown](http://rmarkdown.rstudio.com/), [forecast](https://cran.r-project.org/web/packages/forecast/forecast.pdf),
-[rsqlite](https://cran.r-project.org/web/packages/RSQLite/index.html), [reshape2](https://cran.r-project.org/web/packages/reshape2/reshape2.pdf),
+[rsqlite](https://cran.r-project.org/web/packages/RSQLite/index.html),
 [nycflights13](https://cran.r-project.org/web/packages/nycflights13/index.html), [caret](http://topepo.github.io/caret/index.html),
 [rcurl](https://cran.r-project.org/web/packages/RCurl/index.html), and [randomforest](https://cran.r-project.org/web/packages/randomForest/randomForest.pdf)
 packages from [conda-forge](https://conda-forge.github.io/feedstocks)

r-notebook/Dockerfile

@@ -35,10 +35,8 @@ RUN conda install --quiet --yes -c conda-forge \
     'r-htmlwidgets=1.5*' \
     'r-irkernel=1.1*' \
     'r-nycflights13=1.0*' \
-    'r-plyr=1.8*' \
     'r-randomforest=4.6*' \
     'r-rcurl=1.98*' \
-    'r-reshape2=1.4*' \
     'r-rmarkdown=2.2    *' \
     'r-rodbc=1.3*' \
     'r-rsqlite=2.2*' \