Install new R version on slave machines

The problem

We committed to build the R client for 2 latest R <major>.<minor> version. However the latest R release version (3.5) is inconsistent across platform:

• On Ubuntu, the instruction to install the latest R version gives users R version 3.4.4. This is because the people who manages the artifacts for Ubuntu have not update their artifacts to R 3.5. 
• On Mac, installing R version 3.5 corrupted R version 3.4. Re-installing R version 3.4 removed R version 3.5.

Also, CRAN notes that: "CRAN does not have Mac OS X systems and cannot check these binaries for viruses." 

Proposal

The proposal to solve the problem above is to install from source for all 3 platforms: Linux, Mac, and Windows.

Ubuntu Instructions

• Get the R source from https://cran.r-project.org/ under "R source" link on the left panel.

  Download R source on Ubuntu

  $ wget https://cran.r-project.org/src/base/R-3/R-3.5.0.tar.gz

• Unpack the zip file:

  Unzip

  $ tar -xf R-3.5.0.tar.gz

• Compile the source code:

  Compile

  ./configure
  make

• Then check the built system works correctly by

  check

  make check

• Then install

  install

  make install

Mac Instructions

Windows Instructions