A few linux packages required for R env

In this release, we added a few linux packages, required for installing some R packages in the R Jupyter kernel:

• libcurl4-openssl-dev
• libudunits2-dev
• libfreetype6-dev
• libpng-dev
• libtiff5-dev
• libharfbuzz-dev
• libfribidi-dev
• libfontconfig1-dev
• libgdal-dev

R Kernel + Externalize notebooks

In this release, your Jupyter Lab is endowed with new features:

• 😮‍💨 Support for R Jupyter Kernel
• 2 new Jupyter Lab extensions:
  • 🚀 git : you can now git commit and push any notebook into an external repository
  • 🎸 deck: you can now turn your notebooks into revealjs like powerpoint presentations