r: Set working directory properly
r: Set working directory properly

Set it to /home/rstudio instead of /home/jovyan,
so nbgitpuller & friends run in the correct directory

ryanlovett/datahub,berkeley-dsep-infra/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub,ryanlovett/datahub,berkeley-dsep-infra/datahub