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

sudo make install rhome=/usr/local/R/R-3.5.0

Make link for R <major>.<minor>
make link
```
sudo ln -s R-3.5.0 R-3.5
```

Update the alternatives for R:

update alternatives

sudo update-alternatives --install /usr/bin/R R /usr/local/R/R-3.5/bin/R 50 --slave /usr/bin/Rscript Rscript /usr/local/R/R-3.5/bin/Rscript
sudo update-alternatives --set R /usr/local/R/R-3.5/bin/R

# to view all alternatives
update-alternatives --config R

# to fix broken links
yes '' | sudo update-alternatives --force --all

The problem

Proposal

Ubuntu Instructions

Mac Instructions

Windows Instructions